Again, the chapter begins with “the Lord spoke to Moses,” but now Aaron is added to the team, confirming Aaron’s importance to the concepts that involve worship. This is followed up in verses 2-3, where it states “This is a requirement of the law that the LORD has commanded: Tell the Israelites to bring you a red heifer without defect or blemish and that has never been under a yoke. Give it to Eleazar the priest; it is to be taken outside the camp and slaughtered in his presence.” 

Chapter 18 opens with the rhythms of a phrase we are used to in the Book of Numbers, but with a new ending. So far, most of these chapters have opened with “the Lord said to Moses,” but here, in 18:1, for the first time, it says, “The Lord said to Aaron.” 

The discussion of purification concepts continues, again, taking the legal framework established in the Book of Leviticus laying out the requirements for living the holy, sanctified, sacrificial life that God seemed to expect from the Israelites, and providing practical implementation of those laws.