Interestingly we find passages in the bible which tells us the Missing Torah was found, during the reign of Josiah when he was king of Israel 640-609?
Later on, Hilkiah the high priest informed Shaphan the scribe, "I've discovered the Book of the Law in the LORD's Temple." Hilkiah gave the book to Shaphan, and he began to read it.
(2 kings 22:8)
He went up to the temple of the LORD with the people of Judah, the inhabitants of Jerusalem, the priests and the prophets--all the people from the least to the greatest. He read in their hearing all the words of the Book of the Covenant, which had been found in the temple of the LORD.
(2 kings 23:2)
Furthermore, Josiah got rid of the mediums and spiritists, the household gods, the idols and all the other detestable things seen in Judah and Jerusalem. This he did to fulfill the requirements of the law written in the book that Hilkiah the priest had discovered in the temple of the LORD.
(2 Kings 23:24)
While they were bringing out the money that had been taken into the temple of the LORD, Hilkiah the priest found the Book of the Law of the LORD that had been given through Moses.
(2 Chronicles 34:14)
Hilkiah said to Shaphan the secretary, "I have found the Book of the Law in the temple of the LORD." He gave it to Shaphan.
(2 Chronicles 34:15)
Not convinced with the above passages, To make matters worse we read in Ezra and Nehemiah According to the Hebrew Bible he returned from the Babylonian exile and reintroduced the Torah in Jerusalem....
Nehemiah 8 specifically verses 14 & 17 tells us explicitly how the people were not celebrating the feast laud down by the Torah
14 And they found written in the Law, how that HaShem had commanded by Moses, that the children of Israel should dwell in booths in the feast of the seventh month;
17 And all the congregation of them that were come back out of the captivity made booths, and dwelt in the booths; for since the days of Joshua the son of Nun unto that day had not the children of Israel done so. And there was very great gladness.
They had never celebrated Sukkot (The Feast of Booths) in that country! ("Since the days of Joshua.") Apologists will tell you that the people had simply forgotten the Torah and Ezra was bringing it back to them. However, Richard Friedman points out that in Leviticus 23, the laws for Sukkot seem to be added on to the list of holidays. The list goes from verses 4-37 and ends, "These are the holidays of Hashem." Then, two verses later, it suddenly starts listing the laws of Sukkot. This makes sense in hindsight. Combined with evidence (Neh 8:17, above) that Sukkot wasn't celebrated until Ezra showed up with the Torah, it seems reasonable that Ezra added those verses to an earlier text when he redacted the Torah.
(Friedman brings many more arguments in support of Ezra being the redactor. For example, he points out that this is the first time in all of Tanakh that a finished copy of the Five Books appears)
Talmud tells us It has been taught: R. Jose said: Had Moses not preceded him, Ezra would have been worthy of receiving the Torah for Israel. Of Moses it is written, And Moses went up unto God
Destroy completely all the places on the high mountains, on the hills and under every spreading tree, where the nations you are dispossessing worship their gods.
Break down their altars, smash their sacred stones and burn their Asherah poles in the fire; cut down the idols of their gods and wipe out their names from those places.
Let's read what bible commentators have to say about all this:
Maclaren's Exposition Commentary
We have, first, the discovery of the law. The important and complicated critical questions raised by the narrative cannot be discussed here, nor do they affect the broad lines of teaching in the incident. Nothing is more truthful-like than the statement that, in course of the repairs of the Temple, the book should be found,-probably in the holiest place, to which the high priest would have exclusive access. How it came to have been lost is a more puzzling question; but if we recall that seventy-five years had passed since Hezekiah, and that these were almost entirely years of apostasy and of tumult, we shall not wonder that it was so.
Cambridge Bible for schools and colleges Commentary
8. I have found the book of the law in the house of the Lord] Much discussion has arisen about the discovery which this verse records. Before entering on the question of what it was which Hilkiah found, it may be well to notice briefly the circumstances of the time. Josiah had succeeded his father at the age of eight, and in the previous fifty-seven years the kingdom had twice over been deluged with all the abominations of idolatry. The greater proportion therefore of the inhabitants of Jerusalem would have had little chance of knowing the law and its requirements. The temple had been neglected, perhaps closed, during a large part of these years.
What a shame the evidence is super strong!!!