Question

In the passage describing the Revelation at Mount Sinai (Exodus 19), it says in verse 22: “And also the priests who draw near to the Lord shall sanctify themselves, lest the Lord break out against them.”
In your view, is the mention of the priests in this verse an anachronism? Otherwise it is hard to understand which priests are being referred to here, since the anointing of Aaron and his sons to the priesthood took place many months later.