John Wesley on Exodus 29:4

They were to be consecrated at the door of the tabernacle - God was pleased to dwell in the tabernacle, the people attending in the courts, so that the door between the court and the tabernacle was the fittest place for them to be consecrated in, who were to mediate between God and man, and to stand between both, and lay their hands (as it were) upon both. Here they were to be washed, signifying that they must be clean who bear the vessels of the Lord, Isa 52:11. And they were to be clothed with the holy garments, to signify that it was not sufficient for them to put away the pollutions of sin, but they must put on the graces of the Spirit, be clothed with righteousness, Psa 132:9. They must be girded, as men prepared and strengthened for their work; and they must be robed and crowned, as men that counted their work and office their true honour.