And all the congregation of the people of Israel shall be forgiven, and the stranger who sojourns among them, because the whole population was involved in the mistake.
We have here the laws concerning sacrifices for sins of ignorance; the Jews understand it of idolatry, or false worship, through the error of their teachers. The case here supposed is that they had not observed all these commandments, Num 15:22, Num 15:23.
Commenting on Numbers 15:22-29
And if any soul sin through ignorance,.... Any private or particular person, by breaking any of the above commands, or any other, not rightly understanding them, or not adverting: to the circumstances required in the manner of performing them: then he shall bring a she goat of the first year for a sin offering; which differed in this from the sin offering of a congregation...
Num 15:26 This law was to apply not only to the children of Israel, but also to the stranger among them, “for (sc., it has happened) to the whole nation in mistake.” As the sin extended to the whole nation, in which the foreigners were also included, the atonement was also to apply to the whole.