Leviticus 23:33-44 ESV
And the LORD spoke to Moses, saying, “Speak to the people of Israel, saying, On the fifteenth day of this seventh month and for seven days is the Feast of Booths to the LORD. On the first day shall be a holy convocation; you shall not do any ordinary work. For seven days you shall present food offerings to the LORD. On the eighth day you shall hold a holy convocation and present a food offering to the LORD. It is a solemn assembly; you shall not do any ordinary work.
“These are the appointed feasts of the LORD, which you shall proclaim as times of holy convocation, for presenting to the LORD food offerings, burnt offerings and grain offerings, sacrifices and drink offerings, each on its proper day, besides the LORD’s Sabbaths and besides your gifts and besides all your vow offerings and besides all your freewill offerings, which you give to the LORD.
“On the fifteenth day of the seventh month, when you have gathered in the produce of the land, you shall celebrate the feast of the LORD seven days. On the first day shall be a solemn rest, and on the eighth day shall be a solemn rest. And you shall take on the first day the fruit of splendid trees, branches of palm trees and boughs of leafy trees and willows of the brook, and you shall rejoice before the LORD your God seven days. You shall celebrate it as a feast to the LORD for seven days in the year. It is a statute forever throughout your generations; you shall celebrate it in the seventh month. You shall dwell in booths for seven days. All native Israelites shall dwell in booths, that your generations may know that I made the people of Israel dwell in booths when I brought them out of the land of Egypt: I am the LORD your God.”
Thus Moses declared to the people of Israel the appointed feasts of the LORD.
ESV: English Standard Version 2016