Leviticus 5:6, 9, 12

Then you must bring to the LORD as the penalty for your sin a female from the flock, either a sheep or a goat. This is a sin offering with which the priest will purify you from your sin, making you right with the LORD.

Then he will sprinkle some of the blood of the sin offering against the sides of the altar, and the rest of the blood will be drained out at the base of the altar. This is an offering for sin.

Take the flour to the priest, who will scoop out a handful as a representative portion. He will burn it on the altar on top of the special gifts presented to the LORD. It is an offering for sin.