Midrasch zu Bamidbar 4:27

4) Why is "unwittingly" written both in respect to "se'ir" (the male kid brought by a nassi [a leader (Bamidbar 4:22)]), and "se'irah" (the female kid brought by an individual [Bamidbar 4:27])? (i.e., Why is one not deduced from the other [to exclude a sin-offering for intentional sin])? For there is that in se'ir which is not in se'irah, and that in se'irah which is not in se'ir. Se'ir is used extensively as a communal offering, as opposed to se'irah, (so that if "unwittingly" were written only in respect to se'irah, that would not exclude se'ir as a sin-offering for intentional transgression). Se'irah is used exclusively (by the individual [whether nassi, commoner, or high-priest] for atonement of) idolatry, (so that if "unwittingly" were written only in respect to se'ir, that would not exclude se'irah as a sin-offering for intentional transgression). Therefore, "unwittingly" must be written both in respect to "se'ir" and "se'irah."