Rashi on Numbers 16:28/רש"י על במדבר ט״ז:כ״ח

1לעשות את כל המעשים האלה [HEREBY YE SHALL KNOW THAT THE LORD HATH SENT ME] TO DO ALL THESE THINGS — i.e. that I have acted by the Divine Command in giving Aaron the High Priesthood, and in making his sons second in rank in the priesthood and Elzaphan prince of the Kohathites.