“For seven days you shall offer an offering made by fire to the LORD. On the eighth day you shall have a holy convocation, and you shall offer an offering made by fire to the LORD. It is a sacred assembly, and you shall do no customary work on it” (Leviticus 23.36).
Along with all the other sacrifices going on, the Israelites, or more specifically, the priests had to make sure that they made this special offering that the Lord wanted for seven days.
He had delivered them from Egyptian slavery. Surely, they could keep this feast for seven days as they dwelt in tabernacles, or tents, and had daily burnt offerings.
How much the Lord blesses upon us, and how little in comparison He requires.