Leviticus 4:13-14

13‘Now if the whole congregation of Israel sins unintentionally, and the matter escapes the notice of the assembly, and they have done any one of the things which the Lord has commanded not to be done, and they become guilty;

14when the sin which they have committed becomes known, then the congregation shall offer a young bull of the herd as a sin offering and bring it before the Tent of Meeting.