Mishael and Elzaphan were Aaron’s cousins and second cousins of Nabad and Abihu (Exodus 6:22–23). It is surprising that Aaron’s other sons, Eleazar and Ithamar, are not assigned to the task. Perhaps this is due to the fact that they would become unclean by touching the dead bodies, preventing them from serving in the tabernacle. In Leviticus 21:1–24, we are told that priests are forbidden to go near the dead. This ban was absolute for the high priest (Leviticus 21:10–11), but other priests were allowed to bury their nearest relatives.
4 And Moses called Mishael and Elzaphan, the sons of Uzziel the uncle of Aaron, and said to them, “Come near; carry your brothers away from the front of the sanctuary and out of the camp.”