With which Moses and Aaron and his sons washed is obviously a continuation of verse 30 in Revised Standard Version. Literally the Hebrew says “and Moses and Aaron and his sons washed from it.” The word for “from it” refers to the washbasin mentioned in verse 30, not to the water. Good News Translation translates this as “there” (similarly New American Bible, New Jerusalem Bible, and New Jewish Publication Society’s Tanakh). Their hands and their feet indicates the extent of their washing, and this became the usual ceremonial washing for all priests. (This contrasts with the washing discussed at 29.4.)

When they went into the tent of meeting is literally “in their entering unto [the] ʾohel moʿed.” The infinitive form of the verb “to enter” gives the idea of when, but this should not be understood as a single event. Good News Translation has “whenever,” which really means “each time before entering the tent” (Contemporary English Version). The idea of repeated action comes from the verb they washed, which should be understood in the frequentative sense. And when they approached the altar, literally “and in their approaching unto the altar,” uses the same infinitive form of the verb “to draw near.”

As the LORD commanded Moses is the seventh and last time this formula is used in this chapter. The Hebrew is identical in each case, but Revised Standard Version does not use the word “had” here as in the previous examples. (See the comment at verse 19 above.) New Revised Standard Version has corrected this.

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 .