Rashi on Exodus 40:31/רש"י על שמות מ׳:ל״א

1ורחצו ממנו משה ואהרן AND MOSES AND AARON [AND HIS SONS] LAVED [THEIR HANDS] — On the eighth day of the consecration all of them mentioned here, including Moses, were alike in respect of the priestly office. The translation of ורחצו in the Targum should therefore be ומקדשין, and they were hallowing (i. e. they then hallowed their hands and their feet), for on that day Moses laved his hands together with them (Aaron and his sons).