According to 2 Kings 22-23, in the eighteenth year of the reign of Josiah, the priest Hilkiah found a roll during the renovation work of the Temple of Jerusalem. By order of the king, High Officer Shaphan reads the scroll in front of all the people. The reaction is strong and the king is deeply touched by the curses contained in the book. So he orders the scribes to study of the meaning of what was written in the scroll. The prophetess Huldah in charge of the study, informs the royal officials of the divine judgment that is going to plunge on Jerusalem (see also Jer 19:14 and 7,20, Dt 6:12-15, 31,29, Jdg 2:12 -14a). The King instead will be buried in peace because he had observed the orders contained in the book. Then Josiah reads the book to all the people and announces his intention to make an alliance – in hebr. berit – with Yahweh and he celebrates Easter.
The alliance was an opportunity to undertake deep cultural reform in the Jewish nation. He eliminates the simulacrums of Baal and Ashera and of the celestial army, namely the cult of the sun, the moon and the stars. He destroys the hills – in ebr. bamot – where Yahweh was worshiped and the tofet, an abominable place reserved for human sacrifices. He destroys even Bethel, an officially recognized yahvist sanctuary. From the time of the Fathers of the Church, it was thought that the scroll coincided with the book of Deuteronomy, and that its original edition was edited in the days of Josiah, that is to say, at the end of the seventh century. B.C.
However, the historicity of the discovery poses several difficulties. It cannot be denied that for the Deuteronomists the discovery of the roll is a kind of foundation myth. The text contains some hints on the destruction of Jerusalem and on the Babylonian exile (cf. 22:16-17). Among other things, the motive of the finding of a book is common in ancient literature. It is generally used to justify important changes, whether religious or political. In Mesopotamian shrines there were foundational tablets that were punctually discovered during restoration work. Thomas Römer observes that in some Babylonian royal traditions, the narrative accounts have a very similar pattern to that found in the account of the Second Book of Kings: 1. A king wants to undertake important reforms or changes; 2. there are fears and opposition; 3. one of his servants is invited to a sacred place; 4. here he discovers a book of divine origin; 5. The book encourages the king to undertake his plans. Something like this is also reported in the Sippar cylinder, in which the king Nabonido – who wanted to rebuild the Temple of Ibarra – orders accurate searches to find the foundation stone of the temple in honor of Shamash.
It is likely that the authors of 2 Kings have resorted to the same literary convention. The foundation stone is, in 2 Kings 22-23, the Book of the Law which becomes the foundation of the worship of Yahweh. According to some scholars, the account of the find would have been included in the later age, certainly after the exile.
There is no extra-biblical evidence that confirms the so-called Josiah’s reform, although there are clues in favor of cultural changes at that time. The reference to the horses and chariots of the sun (Shamash, Assyrian goddess) and the kemarin priests, the moon and the army of the sky, are historically plausible for the Assyrian period. Their elimination from the Temple of Jerusalem reflects the diminished influence of Assyria on Syria and Palestine at the end of the seventh century. These are symbols that were no longer fashionable for the political-religious elite at the end of the seventh century as evidenced by seals found in Judah.
Precisely because of this vacuum of Assyrian power, it is plausible that Josiah wanted to centralize in Jerusalem the worship, the power, and the tax activities (generally carried out in sanctuaries). It is also probable that Josiah’s entourage has seen in him the legitimate heir to the Kingdom of Israel. For this reason, the king has been tempted to extend his rule also to the north.
To conclude, the reform of Josiah has some historical foundation, but it is highly unlikely that history has been favored by the discovery of the Book of the Law. However, the first edition of the book of Deuteronomy may well have been made under his realm. Chapters 22-23 of the Second King are important, especially since they might even give us the names of some deuteronomists, such as Hilkiah or the family of Shaphan (see also Jer 36).
According to Römer, 2 Kings 22-23 underwent three subsequent editions. The first, dates back to the Assyrian period, with the removal of the Assyrian cultural symbols and the centralization of worship at Yahve in the restored Temple. After 587 BC, to the story of the prophet Huldah was added the announcement of the destruction of Jerusalem.During the Persian period, the record of the discovery of the book was added. A threefold editing can be recognized almost anywhere in deuteronomic texts.