Leviticus 4:13-14

13‘Now if the whole congregation of Israel sins unintentionally, and the thing is hidden from the eyes of the assembly, and they have done something against any of the commandments of the Lord in anything which should not be done, and are guilty;

14when the sin which they have committed becomes known, then the assembly shall offer a young bull for the sin, and bring it before the tabernacle of meeting.