Charles Ellicott Commentary Leviticus 8:1

"And Jehovah spake unto Moses, saying," — Leviticus 8:1 (ASV)

And the Lord spake unto Moses. —As the consecration of Aaron and his sons to the priesthood which the Lord commanded Moses to establish (Exodus 28:1–43) was to be accompanied by different kinds of sacrifices (Exodus 29:1–37), it was first of all necessary to define the ritual of each sacrifice. This was therefore done in Leviticus 1-7, and the lawgiver now proceeds to record the communication which he received from the Lord concerning the appointment to the sacerdotal office, thus resuming the narrative which was broken off at the end of Exodus.