Ibn Ezra on Leviticus 4:27/אבן עזרא על ויקרא ד׳:כ״ז

1OF THE COMMON PEOPLE. The reference is to all of Israel, the ordinary kohanim and the Levites.

2AND BE GUILTY. Ashem (guilty) is a verb in the perfect. It is like zaken (was old) in when Isaac was old (Gen. 27:1).