Albert Barnes Commentary Leviticus 4:13

"And if the whole congregation of Israel err, and the thing be hid from the eyes of the assembly, and they have done any of the things which Jehovah hath commanded not to be done, and are guilty;" — Leviticus 4:13 (ASV)

Congregation ... assembly - Each of the Hebrew words signifies the people in a collected body. It does not appear that there is any difference between them in the context in which they are used here.