When they go into the tent of meeting, or when they come near the altar to minister, to burn a food offering to the LORD, they shall wash with water, so that they may not die.
Orders are here given, 1. For the making of a laver, or font, of brass, a large vessel, that would contain a good quantity of water, which was to be set near the door of the tabernacle, Exo 30:18. The foot of brass, it is supposed, was so contrived as to receive the water, which was let into it out of the laver by spouts or cocks.
Commenting on Exodus 30:17-21
When they go into the tabernacle of the congregation, they shall wash with water,.... The laver standing near the door of the tabernacle, they washed at it as soon as they entered; and no man, we are told (c), entered into the court before he washed, even though he was clean; though he had contracted no filthiness, and even though he had washed his hands...
They shall wash with water, that they die not - This was certainly an emblematical washing; and as the hands and the feet are particularly mentioned, it must refer to the purity of their whole conduct. Their hands - all their works, their feet - all their goings, must be washed - must be holiness unto the Lord.