Summarize the following court judgment. Civil Appeal No. 1314 of 1978. Appeal by special leave from the judgment and order dated the 23rd March	 1978 of the Allahabad High Court in Civil Revision No. 1906 for 1976. WITH CIVIL APPEAL No. 2436 OF 1981 Appeal by special leave from the judgment and order dated the 20th August	 1981 of the Allahabad High Court in Civil Writ Petition No. 6909 of 1979. AND CIVIL APPEAL No. 1710 OF 1981 From the judgment and Decree dated the 13th March	 1981 of the Allahabad High Court in Writ Petition No. 6167 of 1979. AND SPECIAL LEAVE PETITION (CIVIL) NO. 3573 OF 1979 494 From the judgment and order dated the 3rd January	 1979 of the Allahabad High Court in Civil Revision No. 3714 of 1978. G.L.Sanghi	 Mrs. A. Verma and D.N. Mishra for the Appellant in CA. No. 1314 of 1978. J.P. Goyal	 S.Markandeya and C.K.Ratnaparkhi for the Respondent in CA. 1314 of 1978. A.K. Srivastava for the Appellant in CA. 1710/80. R.B. Mehrotra for Respondent in CA. 1710/80. Pramod Swarup and Mrs. section Markandeya for the appellant in CA. 2436 of 1980. S.N. Kacker and K.K Gupta for the Respondent in CA. 2436 of 1980. P.R.Mridul	 Praveen Jain and K.B. Rohatgi for the Petitioner in SLP (Civil) No. 3573 of 1979 R.H. Dhebar for the Respondent. The Judgment of the Court was delivered by MISRA J. The first two appeals by special leave and the third by certificate and the special leave petition raise a common question of law and	 therefore	 we propose to dispose of them by a common judgment. The pattern of facts in all these cases is similar. We	 therefore set out the facts of Civil Appeal No. 1314 of 1978 to bring out the point for consideration in these matters. The appellant Om Prakash Gupta is a tenant of a shop on a monthly rent of Rs. 150/ .The respondent landlord filed a suit for the eviction of the tenant on the ground that the U.P. Urban Buildings (Regulation of Letting	 Rent and Eviction) Act	 1972 (Act 13 of 1972 and hereinafter referred to as 'the Act ') did not apply to the shop and the tenant was liable to eviction. The Judge	 Small Causes Court	 Mainpuri decreed the suit on the finding inter alia that the construction of the shop in suit was completed in the year 1967 and 495 that ten years having not elapsed since then	 the provisions of the Act did not apply to the case. The defendant went up in revision under section 25 of the Provincial Small Causes Courts Act against the judgment and decree of the trial Court but the same was substantially dismissed. The defendant thereupon filed a revision under section 115 of the Civil Procedure Code in the High Court which came up for hearing before a learned Single Judge who remitted the following issue to the trial court: "On what date was the construction of the building in dispute completed within the meaning of section 2 (2) of the U.P. Urban Buildings (Regulation of Letting	 Rent and Eviction) Act	 1972	 and deemed to have been completed as contemplated by Explanation I (a) thereto. " The Judge Small Causes Court by his order dated 26th of November 1977 returned the following finding: "The construction of the disputed shop will be deemed to have been completed on the date of the first assessment i.e. 1.4.68 within the meaning of section 2 (2) of the U.P. Urban Buildings Act	 1972. " The finding returned by the trial court was sought to be challenged on behalf of the tenant on the ground that the date of occupation should be taken to be the date of completion of the construction of the shop and not the date of the first assessment. In Tilak Raj vs Sardar Devendra Singh	(1) a learned Single Judge of the same High Court had the occasion to consider section 2 (2) of the Act. He held: "It is apparent from this provision that for purposes of this Act	 a building is to be deemed to be constructed	 if it is subject to assessment	 on the date with effect from which the first assessment is made. It is immaterial whether the building was constructed actually prior to that date or it had come into occupation prior to that date. The law recognised for the purposes of this Act	 the date of assessment as the date of the completion of the building. There is thus no error in the judgment of the court below. " 496 The learned Single Judge before whom the revision in the instant case came up for hearing doubted the correctness of the above decision. He	 therefore	 referred the case to a Division Bench. There is no dispute that the first assessment of the shop took place on 1st of April	 1968. It is also not in dispute that the shop in question was occupied by the defendant on 16th of June	 1967	 and prior to his occupation the shop was in occupation of another tenant for about a month and a half. The appellant sought the benefit of section 39 of the Act on the ground that if the date of occupation was taken to be the date of the completion of the construction of the shop	 then ten years having elapsed during the pendency of the revision before the High Court	 the Act would be applicable. The Division Bench	 however	 over ruled the contention of the appellant and held that the construction of the shop in question would be deemed to have been completed on 1st of April 1968 and	 therefore	 the Act would not be applicable to the building till the date of the decision of the revision on March 23	 1968. The defendant undaunted by the failure came to this Court to challenge the judgment of the High Court. Mr. G.L. Sanghi	 senior counsel. appearing for the appellant strongly contended that on a correct interpretation of sub section (2) of section 2	 the Act would be applicable to the shop in question. It would be appropriate at this stage to extract sub section (2) of section 2 of the Act insofar as it is material for the purposes of the case: "Except as provided in sub section (5) of section 12	 sub section (1 A) of section 21	 sub section (2) of section 24	 sections 24A	 24B	 24C or sub section (3) of section 29	 nothing in this Act shall apply to a building during a period of ten years from the date on which its construction is completed: Explanation I. For the purposes of this sub section: (a) the construction of a building shall be deemed to have been completed on the date on which the completion thereof is reported to or otherwise recorded by the local authority having jurisdiction and in the case of a building subject to assessment the date on which the first assessment thereof 497 comes into effect	 and where the said dates are different	 the earliest of the said dates	 and in the absence of any such report	 record or assessment	 the date on which it is actually occupied (not including occupation merely for the purposes of supervising the construction or guarding the building under construction) for the first time :. " The precise contention on behalf of the appellant is that the exemption created by this sub section does not embrace buildings constructed prior to the enforcement of the Act. In support of his contention	 Mr. Sanghi	 relied upon Rattan Lal Shinghal vs Smt. Murti Devi.(1) The same contention was raised by him in that case also and a Division Bench of this Court accepted the contention and held that Act 13 of 1972 was prospective and applied only to buildings brought into being de novo after the Act came into force. In that case there is no discussion except this bald observation. This Court in a subsequent case Ram Saroop Rai vs Lilavati(2) held to the contrary. It is on this account that the present appeals were referred to a larger Bench. There is no ambiguity in the language of sub section (2) of section 2 and in the absence of any ambiguity there is no question of taking any external aid for the interpretation of the sub section. In plain words the sub section contemplates that the Act shall not apply to a building during a period of ten years from the date on which its construction is completed. It nowhere says that the building should have been constructed after the enforcement of the Act and to interpret it in the way the learned counsel for the appellant seeks to interpret it	 we would be adding words to the sub section	 which is not permissible. Primarily the language employed is the determining factor of the intention of the legislature. The first and primary rule of construction is that the intention of the legislature must be found in the words used by the legislature itself. The question of interpretation arises only when the language is ambiguous and	 therefore	 capable of two interpretations. In the present case the language of sub section (2) of section 2 of the Act is explicit and unambiguous and it is not capable of two interpretations. 498 As a second limb to the first argument	 it is contended that the building will be deemed to have been constructed on the date of occupation on 16th of June	 1967 and not on the date of the first assessment	 and that if this be so	 the appellant would be entitled to the benefit of section 39 of the Act on the date when the revision came to be decided by the High Court on 23rd of March	 1978. In order to appreciate this argument it will be expedient to refer to Explanation I to sub section (2) of section 2 which has already been extracted. Explanation I provides that the building shall be deemed to have been completed on the date on which completion thereof is reported to or otherwise recorded by the local authorities having jurisdiction	 and in case of a building subject to assessment the date on which the first assessment thereof comes into effect and where the said dates are different	 the earliest of the said dates	 and in the absence of any such report	 record or assessment	 the date on which it is actually occupied for the first time. A perusal of Explanation I makes it abundantly clear that the date of occupation would be taken to be the date of completion of the construction only when there is no report or record of the completion of the construction or no assessment	 thereof. If there is an assessment	 as in the present case it is	 it will be the date of the first assessment which will be deemed to be the date of completion of the construction and in that view of the matter the building had not become more than ten years ' old on the date when the revision came to be decided by the High Court	 and therefore there was no question of giving the benefit of section 39 of the Act to the appellant. Further	 in order to attract section 39 the suit must be pending on the date of commencement of the Act which is 15th of July	 1972 but the suit giving rise to the present appeal was filed on 23rd of March	 1974 long after the commencement of the Act. There is yet another reason why section 39 will have no application to the present case. In view of sub section (2) of section 2 of the Act the Act is not applicable to a building which has not a standing of ten years and if the Act itself was not applicable	 it would be absurd to say that section 39 thereof would be applicable. Considered from any angle the Act has no application to the present case and the appellant could not be given the benefit of section 39. The suit has	 therefore	 been rightly decreed by the courts below. We find no force in either of the contentions raised by Mr. Sanghi. The counsel for the appellants in the other appeals and 499 the petitioner in the special leave petition	 adopted the arguments of Mr. Sanghi. For the foregoing discussion the appeals and the special leave petition are dismissed. There shall	 however	 be no order as to costs. We	 however	 direct that the order of eviction in each case shall not be executed before 30th of June	 1982 on condition that each of the appellants in the appeals and the petitioner in the special leave petition files an undertaking in this Court within four weeks from today to the following effect: 1. that he will hand over vacant and peaceful possession of the suit premises to the landlord respondent on or before 30th of June	 1982; 2. that he will pay to the respondent arrears of rent	 if any	 within a month from today; 3. that he will pay to the respondent future compensation for use and occupation of the suit premises for each calendar month by the 10th of the succeeding month; and 4. that he will not induct any other person in the suit premises as a sub tenant or licensee or in any other capacity whatsoever. We further direct that in default of compliance with any one or more of the conditions of the undertaking or if the undertaking is not filed within the stipulated time	 the decree of eviction shall become executable forthwith. N.V.K. Appeal dismissed.

The U.P. Urban Buildings (Regulation of Letting	 Rent and (Eviction) Act	 1972 provided by sub section (2) of section 2 that except as provided in the Act	 the Act was not to apply to a building during a period of 10 years from the date on which its construction was completed. Explanation I to the sub section provided that the building shall be deemed to have been completed on the date on which completion thereof is reported or otherwise recorded by the local authorities having jurisdiction	 and in case of a building subject to assessment	 the date on which the first assessment thereof comes into effect	 and where the said dates are different	 the earliest of the said date	 and in the absence of any such report	 record or assessment	 the date on which it is actually occupied for the first time. The appellant tenant was in occupation of a shop from the 16th June	 1967 and prior to his occupation the shop was in occupation of another tenant for about a month and a half. The first assessment of the shop took place on Ist of April	 1968. The respondent landlord filed a suit for the eviction of the tenant on the ground that the Act did not apply to the shop and the tenant was liable to eviction. The Trial Judge finding that the construction of the shop was completed in the year 1967 and that 10 years having not elapsed since then	 held that the provisions of the Act did not apply and decreed the suit. The appellant 's 492 petition under section 25 of the Provincial Small Causes Courts Act was dismissed. In his revision petition to the High Court under section 115 of the Civil Procedure Code the appellant contended that the date of occupation should be taken to be the date of completion of the construction of the shop and not the date of first assessment. The High Court overruled the contention and held that the construction of the shop would be deemed to have been completed on 1st of April	 1968 the date of the first assessment and ten years not having elapsed	 the Act would not be applicable to the building and dismissed the revision petition. In the appeal to this Court it was contended on behalf of the appellant: (1) that by virtue of sub section (2) of section 2	 the Act would be applicable to the shop in question and that the exemption created by the sub section did not embrace buildings constructed prior to the commencement of the Act and (2) that the building should be deemed to have been constructed on the date of occupation on 16th June	 1967 and not on the date of the first assessment. and that the appellant was entitled to the benefit of section 39 of the Act. Dismissing the appeal	 ^ HELD: 1(i) The suit was rightly decreed by the Courts below. The Act had no application and the appellant could not be given the benefit of section 39. [498 G H] (ii) Primarily	 the language employed is the determining factor of the intention of the legislature. The first and primary rule of construction is that the intention of the legislature must be found in the words used by the legislature itself. The question of interpretation arises only when the language is ambiguous and	 therefore capable of two interpretations. [497 F] (iii) The language of sub section (2) of section 2 of the Act is explict and unambiguous and is not capable of two interpretations. [497 G] In the absence of any ambiguity there is no question of taking any external aid for the interpretation of the sub section. The sub section contemplates that the Act shall not apply to a building during a period of 10 years from the date on which its construction is completed. It no where says that the building should have been constructed after the enforcement of the Act and to interpret it in such a way would be to add words to the sub section	 which is not permissible. [497 D F] 2 (i) Explanation I makes it abundantly clear that the date of occupation would be taken to be the date of completion of the construction only when there is no report or record of the completion of the construction or no assessment thereof. If there is an assessment	 as in the instant case it will be the date of the first assessment which will be deemed to be the date of completion of the construction. The building had not therefore become more than ten years 's old on the date when the revision came to be decided by the High Court and consequently there was no question of giving the benefit of section 39 of the Act to the appellant. [498 D F] 493 (ii) In order to attract section 39 the suit must be pending on the date of the commencement of the Act which was 15th of July	 1972. [498 F] In the instant case the suit was filed on 23rd of March 1974 long after the commencement of the Act. [498 F] (iii) In view of sub section (2) of section 2	 the Act is not applicable to a building which has not a standing of ten years. If the Act itself was not applicable	 it would be absurd to say that section 39 thereof would be applicable. [498 G] Rattan Lal Shinghal vs Smt. Murti Devi (1980)4 S.C.C. 258 and Ram Saroop Rai vs Lilavati ; 	 over ruled.