John Gill Commentary Leviticus 7:1

"And this is the law of the trespass-offering: it is most holy." — Leviticus 7:1 (ASV)

Likewise this [is] the law of the trespass [offering]
Or the various rites and rules to be observed at the offering of it: the persons for whom it was to be made are described in the two preceding chapters, (Leviticus 5:1–6:30) both such that sinned through ignorance, and knowingly, and here the place and parts of the offering, and how to be disposed of, are declared:

it [is] most holy ;
wholly devoted for sacred use, either to the Lord, or to his priests; there were some things the Jews call light holy things, and others most holy in the highest degree, of this sort was the trespass offering.