Nehemiah 8:18
"Also day by day, from the first day unto the last day, he read in the book of the law of God. And they kept the feast seven days; and on the eighth day was a solemn assembly, according unto the manner."
Cross References (ranked by relevance)
Leviticus 23:36
Seven days ye shall offer an offering made by fire unto the LORD: on the eighth day shall be an holy convocation unto you; and ye shall offer an offering made by fire unto the LORD: it is a solemn assembly; and ye shall do no servile work therein.
Numbers 29:35
On the eighth day ye shall have a solemn assembly: ye shall do no servile work therein:
John 7:37
In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink.