Exodus 28:41
And thou shalt put them upon Aaron thy brother, and his sons with him; and shalt anoint them, and consecrate them, and sanctify them, that they may minister unto me in the priest’s office. And thou shalt put them upon Aaron thy brother, and his sons with him; and shalt anoint them, and consecrate them, and sanctify them, that they may minister unto me in the priest’s office.
The verse appoints specific garments for Aaron and his sons, in which they were to be clothed and anointed and consecrated and sanctified to minister in the priest's office, and their ministry required purity before a holy God, with every particle of dust washed away before entering His presence, since failure to meet these conditions brought death. God gave Moses special and detailed directions for everything connected with tabernacle service, specifying the dress of those who minister in His service and requiring order in all things and especially cleanliness, with particular directions for the garments of those serving in the tabernacle. Aaron's robes were symbolic, showing that God has a preference about the dress of those who serve Him.
The apparel of those who officiate before God can honor or dishonor Him. Those in sacred office must show reverence and care in dress and conduct, and their cleanliness and order teach the people that God is holy, His work is sacred, and impurity must be put away by those who approach Him. As with the priests, Christ's followers are to dress symbolically, representing Him in all things.