Albert Barnes Commentary Nehemiah 8:17

"And all the assembly of them that were come again out of the captivity made booths, and dwelt in the booths; for since the days of Jeshua the son of Nun unto that day had not the children of Israel done so. And there was very great gladness." — Nehemiah 8:17 (ASV)

It is not the intention of the writer to state that the Feast of Tabernacles had not been kept from the time of Joshua until this occasion (see 1 Kings 8:2, 1 Kings 8:65; Ezra 3:4); but that there had been no such celebration as this since Joshua’s time. Compare 2 Kings 23:22; 2 Chronicles 35:18.