Matthew Poole and continuators on Exodus 19:22

22 And let the Priests also which come near to the LORD sanctifie themselves, lest the LORD break forth upon them.

For though the Aaronical Priesthood was not yet appointed, it is certain, that as there were sacrifices before, so there were Priests to offer them, which were either the first born who were consecrated [illegible: 1+ letters]o God and did execute the office of Priests, as may be gathered from Exod. 13. 2. and 24. 5. Numb. 3. 12. and 8. 26. or some other persons appointed by God for doing that work till the office was settled in Aarons family.

Not at this time, for both Priests and people are now kept at equal distance, ver. 22. but usually, q. d. whose duty and priviledge it is to approach unto God and to present the peoples prayers and sacrifices to him and therefore are here particularly admonished, because they above all others are obliged to this care, and because they might seem to claim this priviledge by their function.