In fourth aliyah, Moshe anoints Aharon and his sons to be the Kohane Gadol (high priest), and priests, respectively, and serve in the Mishkan (the tabernacle in the desert). Moshe assembles all the Jewish people and immerses Aharon and his sons in the mikvah. Then he dresses them in their priestly garments, and anoints the Mishkan and all its contents, as well as Aharon and his sons, with the holy anointing oil.