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.
Related Commentaries of Nehemiah 8:17
Nehemiah 8:17
17 And all the congregation of them that were come again out of the captivity made booths, and sat under 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.