Here the consecration of Aaron and his sons and the directives given by God to Moses is highlighted, the first step that he orders is about the calf of the atonement which refers to the first step in the ordination of a priest, it is about of the purification offering, this ceremony is also explained in Exodus 29.35-39
Then he says that he poured the anointing oil over Aaron's head; the anointing separated Aaron for the service of the priesthood, for the fulfillment of his sacred mission, both the kings and the priests were anointed to serve the congregation as God-appointed leaders, even the pagan monarch Cyrus is mentioned as the anointed of the Lord (Messiah), due to the task that had been entrusted, the authors of the writings preserved in the Dead Sea scrolls speak of two messiahs (the anointed ones), Aaron and David, which seems to show that they expected God to send them to a priest and a king as Messiah in the last days, Jesus took the term "anointed" from Isaiah 61.1 when he spoke of his messianic task (Luke 4.18), hence the term "Christ", which technically is not a proper name, but the Greek expression of the Hebrew word maschiaach (messiah)but the Greek expression of the Hebrew word maschiaach (messiah)