You shall bring Aaron and his sons uses the same verb as in verse 3. To the door of the tent of meeting is literally “unto the opening of the ʾohel moʿed.” As explained at 33.7, “tent of meeting” reflects a different tradition, but the term is often used in reference to the mishkan, or tabernacle. The context is clear that this is the “entrance” of the tabernacle (Good News Translation), which was to be covered by a “screen,” not by a door. (See 26.36.)

And wash them with water is literally “and you [singular] will wash them in water.” This means that Moses was to wash Aaron and his sons. The word for wash suggests pouring, in contrast with the word for washing clothes. (See 19.10 and the comment there). The extent of this ritual washing is not indicated, but it probably included the entire body, since this was different from the later ceremonial washing performed by the priests themselves (as described in 30.17-21). Good News Translation‘s “have them take a ceremonial bath” may be misleading, as it suggests that they did the washing rather than Moses. Contemporary English Version even has “have them wash themselves,” but translators should not follow this as a model.

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .