And Aaron and his sons you shall bring unto the door of the tabernacle of meeting, and shall wash them with water.
All Commentaries on Exodus 29:4 Go To Exodus 29
Cyril of Jerusalem
AD 386
The high priest washes himself, then offers incense; for Aaron was first washed, then became high priest. For how could one who had not yet been cleansed by water pray for others? Further, the laver had been set within the tabernacle, as a symbol of baptism.