When was the tanakh edited?

Answer 1

The 120 Men Of The Great Assembly (Anshei Knesseth HaGedolah) is the title given to the Sanhedrin during the early years of the Second Temple. According to Talmudic chronology, this was about 2360 years ago, and during the first few decades following. In addition to composing the Siddur (prayerbook) and enacting the bulk of the Rabbinical decrees, it was they who sealed the canon of the Tanakh and, with Ruach HaKodesh (Divine inspiration), added whatever edits the Tanakh contains that had not been included by the prophets themselves. The years in which the Great Assembly functioned were the closing years of the prophetic era, and they knew that no later Sages would ever feel the authority to add anything in the Tanakh.

The aforementioned edits may have included the placing of the dots (not vowel points, but unique marks) on the letters that have them (such as in Deuteronomy 29:28), big letters (such as in Deuteronomy 6:4), small letters (such as in Genesis 23:2), words that are pronounced differently than their spelling (such as in many of the verses in Lamentations ch. 5), and letters that are shaped or positioned unusually (such as in the end of Numbers ch. 10). The Great Assembly also put the proplets' books in their present order.

It may be noted in passing, that two other minor edits took place. One is alluded to in Proverbs 25:1, where it is stated that the Sages in the time of Chizkiah (Hezekiah) collated the latter verses of Proverbs. The other is mentioned in the Talmud (Megillah, page 7a), that the Sages of the Mishnah (about 1880 years ago) considered whether one or more of the five Megilloth should have minor status compared to the others.