Charles Ellicott Commentary Numbers 15:24

"then it shall be, if it be done unwittingly, without the knowledge of the congregation, that all the congregation shall offer one young bullock for a burnt-offering, for a sweet savor unto Jehovah, with the meal-offering thereof, and the drink-offering thereof, according to the ordinance, and one he-goat for a sin-offering." — Numbers 15:24 (ASV)

By ignorance. —The word shegagah is used to denote transgressions committed unwittingly in contrast to sins committed presumptuously (Numbers 15:30). (See Leviticus 4:2 and Note.) Provision had already been made in Leviticus 4:0 for sins of commission committed unwittingly by the whole congregation, but no provision appears to have been made for the guilt contracted in the case of sins of omission.

It is possible, also, that in this place transgressions committed by an individual, but affecting the whole of the congregation, may be included. In Leviticus 4:14 a young bullock is appointed as a sin offering; in the present case a young bullock is appointed for a burnt offering and a kid of the goats for a sin offering. It must be remembered, moreover, that the commandments delivered in this chapter have express reference to the land of Canaan, whereas many of the commandments previously delivered had already become obligatory.