"On the eighth day you are to hold a solemn assembly; you are not to do any daily work.
References for Numbers 29:35
Present a burnt offering, a fire offering as a pleasing aroma to the Lord: one bull, one ram, seven male lambs a year old-[all] unblemished-
with their grain and drink offerings for the bulls, rams, and lambs, in proportion to their number.
Also [offer] one male goat as a sin offering. These are in addition to the regular burnt offering with its grain and drink offerings.
"You must offer these to the Lord at your appointed times in addition to your vow and freewill offerings, whether burnt, grain, drink, or fellowship offerings."
So Moses told the Israelites everything the Lord had commanded him.
References for Numbers 29:40