Adam Clarke on Numbers 29:35

On the eighth day ye shall have a solemn assembly - This among the Jews was esteemed the chief or high day of the feast, though fewer sacrifices were offered on it than on the others; the people seem to have finished the solemnity with a greater measure of spiritual devotion, and it was on this day of the feast that our blessed Lord called the Jews from the letter to the spirit of the law, proposing himself as the sole fountain whence they could derive the streams of salvation, Joh 7:37. On the subject of this chapter see the notes on Lev 12:1-8 (note), Leviticus 16 (note), Leviticus 23 (note).