According to the author of the book of Leviticus, this means that God told the people to burn the fat of the sacrificed animal on the altar as a way to say sorry for doing wrong things. It's like a special way to show God that they wanted to make things right.
Leviticus 16:25: And the fat of the sin offering shall he burn upon the altar.
These verses suggest that God does not delight in burnt offerings, which contradicts Leviticus 16:25's emphasis on the importance of such offerings.
Amos 5:21-22: I hate, I despise your feast days, and I will not smell in your solemn assemblies. [in...: or, your holy days]