It is a trespass offering: he has certainly trespassed against the LORD.
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George Leo Haydock
AD 1849
Lord. Hebrew, "It is a victim for the sin which he has committed against the Lord. "From this chapter, as well as from Numbers v. 7, it is obvious that a special confession was necessary, not only for those who had fallen into the disorder of leprosy, which was a figure of sin, and often inflicted by God in punishment of it; but also, when they had given way to the smallest transgression against the commands and ceremonies of the Lord. (Haydock)
This custom is still observed by the Jews. (Galatinus x. 3.)