Leviticus 5:10, 12, 18

And he shall offer the second for a burnt offering, according to the manner: and the priest shall make an atonement for him for his sin which he hath sinned, and it shall be forgiven him.

Then shall he bring it to the priest, and the priest shall take his handful of it, even a memorial thereof, and burn it on the altar, according to the offerings made by fire unto the LORD: it is a sin offering.

And he shall bring a ram without blemish out of the flock, with thy estimation, for a trespass offering, unto the priest: and the priest shall make an atonement for him concerning his ignorance wherein he erred and wist it not, and it shall be forgiven him.