Albert Barnes Commentary Leviticus 4:22

"When a ruler sinneth, and doeth unwittingly any one of all the things which Jehovah his God hath commanded not to be done, and is guilty;" — Leviticus 4:22 (ASV)

Ruler - Either the head of a tribe (Numbers 1:4–16), or the head of a division of a tribe (Numbers 34:18).