Mesad Hashavyahu Meṣad Hashavyahu is an ancient fortress on the border of ancient Judea facing the Philistine city of Ashdod near the Mediterranean Sea . It lies 1 . 7 km south of Yavne - Yam ( the seaport ) and 7 km northwest of Yavne ( the main city ) . The original name of the fort is unknown , but was given the name found on several inscribed pottery shards ( ostraca ) recovered at the site . The site covers an area of approximately . History . It dates from approximately 630 BCE to 609 BCE , within the reigning years of Josiah , king of Judah . W . F . Albright wrote , " The life of the fortress could be dated within narrow limits by the typical late pre - exilic and early Ionian pottery found on the site , as well as by historical considerations , which suggest a date about 630 BCE . This would be just after the death of the Assyrian king Ashurbanipal and before the occupation of the Philistine Plain by Psammetichus of Egypt . " Some scholars believe the site had been used by Greek mercenaries in the employ of the Judaean king in his battles against the Egyptian army . But there were also Judahite mercenaries in the Egyptian army at the time of the late monarchic period . According to Israel Finkelstein , " it is therefore quite reasonable that the unit stationed in the Egyptian fort of Messad Hashavyahu included Judahite mercenaries " . Others , such as Israel Finkelstein and Nadav Naaman , believe this site was controlled by the Egyptians and not Josiah : " in any event , regarding Mesad Hashavyahu , there can be little doubt that Egypt , which expanded in the late 7th century [ BCE ] along the coast of the Levant , was strong enough to prevent Josiah from building an isolated fort in the middle of an area in which Egypt had strong strategic interests " . One of the significant issues dependent on this debate is whether or not the Kingdom of Judah under Josiah had access to a sea port . The fact that the fort was south - facing may imply that it was built for the protection of Yavne and the surrounding agricultural lands including the seaport area of Yavne - Yam , against aggressors from the south , either Philistine or Egyptian . The fortress was abandoned in 609 BCE or shortly thereafter , likely associated with the loss of territory due to occupation by the Egyptian army following Josiah ' s death . It was excavated by Joseph Naveh in 1960 . The Mesad Hashavyahu ostracon . One of the most important finds at Mesad Hashavyahu is an ostracon containing a written appeal by a field worker to the fortress ' s governor regarding the confiscation of his cloak , which the writer considers to have been unjust . The worker makes his appeal to the governor on the basis of both the garment ' s undeserved confiscation and by implication , the biblical law regarding holding past sundown a person ' s cloak as collateral for a debt ( Exodus 22 . 26 - 27 ; cf . Deut 24 . 12 - 13 ) . Although the petition does not specifically cite the law , it would have been commonly known by rulers and peasants alike . The ostracon also bears the first known extra - Biblical reference to the Hebrew Sabbath day of rest ( Saturday ) . Concerning who was in control of this area of the Philistine Plain , Shmuel Ahituv states , " The letter is written in good biblical Hebrew , plus a possible scribal omission here or there , and the script is that of a trained scribe . The work supervisor mentioned in the text bears a clearly Judaean name , Hoshavyahu . All these factors point to a time of Judaean control over the area . " Naveh agrees , " The four Hebrew inscriptions together testify to this fortress having been under Judaean control at the time . . . . It seems likely that Josiah placed a military governor in charge of the fortress , and that the force garrisoned there was supplied with provisions by the peasants living in the unwalled settlements in the vicinity . " The ostracon was found under the floor of a room adjacent to the guardhouse / gate complex , is approximately 20 cm high by 16 . 5 cm wide , and contains 14 visible lines of text . In all , seven key artifacts were recovered , six of them inscribed ostraca in the Hebrew language . Pottery shards in the layer above represented Greek ( early Ionian / Southwest Anatolian ) or Persian - period pottery . The ostraca from this site are currently located in the Israel Museum at Jerusalem . Translation . The following is a translation of the ostracon , which is composed of fourteen lines in Hebrew : Due to breaks in the ostracon and a missing lower right section , Naveh states that there are too few letters available in line 13 to make an educated guess what it said . The same might likely be said of lines 11 through 14 , which have been reconstructed , and a line 15 which is missing .