Exodus 28:1
And take thou unto thee Aaron thy brother, and his sons with him, from among the children of Israel, that he may minister unto me in the priest’s office, even Aaron, Nadab and Abihu, Eleazar and Ithamar, Aaron’s sons. And take thou unto thee Aaron thy brother, and his sons with him, from among the children of Israel, that he may minister unto me in the priest’s office, even Aaron, Nadab and Abihu, Eleazar and Ithamar, Aaron’s sons.
The command to take Aaron and his sons to minister in the priest's office is instruction from Christ Himself, enshrouded in the pillar of cloud while educating His church in the wilderness, and it belongs to the outline of God's expressed will for the mental, physical, and moral improvement of the whole being. God took Aaron with his sons Nadab and Abihu, Eleazar and Ithamar from among the children of Israel to minister in the priest's office, thereby conferring the priesthood upon Aaron's family and male descendants and honoring Aaron himself with sacred consecration as high priest. The priesthood was an assigned order not to be claimed or seized by others, and Korah's desire for that dignity and attempt to force a change opposed the order God had established.
God gave special and particular directions prescribing garments suited to the priests' work, and Aaron's robes were symbolic, showing that He requires order in everything connected with His service. He may be honored or dishonored by the apparel of those who officiate before Him, and He requires especially cleanliness in His service. Before entering His presence the priests had to wash their hands and feet at the laver, showing that every trace of defilement had to be removed because God is so holy that failure to meet these conditions meant death. Aaron's sons Nadab and Abihu disobeyed God's command about the fire offered with incense by bringing common fire instead of sacred fire, and God's fire destroyed them, showing the grave consequences of disregarding God's directions in priestly service.
Dress matters to God, and the clothing of Christ's followers should also be symbolic, representing Christ in all things by being neat, modest, and pure, not changed merely to follow fashion or display vanity. The verse declares God's covenant with the people He is seeking to save today and the terms of salvation, giving the education of most value and the highest knowledge a human being can possess, the knowledge of the only true God and Jesus Christ whom He has sent.