There is one law for them. — That is, the same rule, as stated in Leviticus 6:27-28, applies to both the sin offering and the trespass offering; hence what is omitted in the regulation of the one must be supplied from the directions given in the other.
Related Commentaries of Leviticus 7:7
Leviticus 7:7
7 As the sin offering is, so is the trespass offering: there is one law for them: the priest that maketh atonement therewith shall have it.