And it shall be upon Aaron means, as Good News Translation has it, that “Aaron is to wear this robe.” When he ministers is literally “to serve.” The word always refers to a high form of service and is often used for the official services of a priest. (See verse 43.) Here it refers to the prescribed duties of the high priest inside the tabernacle. And its sound shall be heard refers to “the sound of the bells.” When he goes into the holy place is literally “in his entering unto the holy [place].” (See the comment at 26.33.) Before the LORD is literally “to the face of Yahweh.” Since Yahweh is the speaker, Good News Translation changes to “when he comes into my presence.” And when he comes out is literally “and in his exiting.”

Lest he die, literally “and he will not die,” probably means “so that he will not die” (New International Version). Some scholars suggest that the “sound of the bells” (Good News Translation) was necessary to frighten away demons, while others say it was to signal to the priests and the people outside that the high priest was actually performing the sacred rituals. It is also possible that the phrase, lest he die, refers not only to the “sound of the bells,” but also to the need for wearing the robe “when he serves as priest” (Good News Translation and similarly Contemporary English Version).

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 .