Leviticus 5:11-12

11“But if he cannot afford two turtledoves or two young pigeons, he may bring two quarts of fine flour as an offering for his sin. He must not put olive oil or frankincense on it, for it is a sin offering.

12He is to bring it to the priest, who will take a handful from it as its memorial portion and burn it on the altar along with the food offerings to the Lord; it is a sin offering.