" The validity of this rule was also recognised in Baleshwar Bagarti vs Bhagirathi Dass(1) where Mookerjee, J. stated the rule in these terms: "It is a well settled principle of interpretation that courts in construing a statute will give much weight to the interpretation put upon it, at the time of its enactment and since, by those whose duty it has been to construe, execute and apply it." and this statement of the rule was quoted with approval by this Court in Deshbandhu Guptu & Co. vs Delhi Stock Exchange Association Ltd.(2) It is clear from these two circulars that the Central Board of Direct Taxes, which is the highest authority entrusted with the execution of the provisions of the Act, understood sub section (2) as limited to cases where the consideration for the transfer has been under stated by the assessee and this must be regarded as a strong circumstance supporting the construction which we are placing on that sub section.