To emphasize the importance of maintaining proper interpersonal relationships within the camp Moses repeated the law concerning the restitution of and compensation for a trespass against one's neighbor here (cf. Lev. 5:14-6:7). The expression "sins of mankind"(v. 6) can refer to sins committed bya human being and to sins committed againsta human being.37The context favors the latter option.
Added instructions covered another case. This was a person who could not fulfill his responsibilities because the person against whom he had committed the trespass, or that person's near kinsman, had died or did not exist. In this case the guilty party had to make restitution and compensation to the priests (v. 8).
Trespasses against one's neighbor (cf. Lev. 6:1-7) needed atonement because they constituted acts of "unfaithfulness"to God (v. 6).
The Israelites had to maintain proper horizontal relationships with their brethren to maintain a proper vertical relationship with Yahweh (cf. Matt. 5:23-24).
"The point is clear--wrongs committed against God's people were considered wrongs committed against God himself."38