Shemot 40:31

31 And Moshe and Aharon and his banim washed their hands and their feet thereat;

Shemot 40:31 Meaning and Commentary

Exodus 40:31

And Moses, and Aaron, and his sons, washed their hands and
their feet thereat.
] This laver was for the priests, and Moses, officiating as a priest, washed in it, with Aaron, and his sons, whom he was now about to consecrate to the priest's office, and invest with it by offering sacrifice for them; Jarchi says this was on the eighth day of the consecration.

Shemot 40:31 In-Context

29 And he put the Mizbe’ach HaOlah at the Petach Mishkan Ohel Mo’ed, and offered upon it the olah (burnt offering) and the minchah; as Hashem commanded Moshe.

30 And he set the Kiyor between the Ohel Mo’ed and the Mizbe’ach, and put mayim there, to wash withal.

31 And Moshe and Aharon and his banim washed their hands and their feet thereat;

32 When they went into the Ohel Mo’ed, and when they came near unto the Mizbe’ach, they washed; as Hashem commanded Moshe.

33 And he erected the khatzer (courtyard) all around the Mishkan and the Mizbe’ach, and set up the Masach Sha’ar HaKhatzer. So Moshe finished the work.