The OT priests began their daily ministry adorned in white garments which became stained with blood through the course of the day, and would have to be washed for the next day’s ministry. The Gospel priesthood deepens this picture. It extends the expected call to wash our robes, but surprises us by having us wash them in the blood of the Lamb, and in so doing our robes become white (Rev. 7:14). Their robes began white and ended bloodstained. Our robes begin bloodstained and end white.
This water is a sign of both the blood, and the robes made white by that blood. In baptism we receive white robes, made clean not by the dead works of unbelief but by the blood of Jesus. By His righteous work we are sanctified, and given new hearts of faith. Apart from Christ we wear filthy rags, soiled with the uncleanness of the flesh. But through Christ, the saints are given white robes, bleached with blood, signified by these baptismal waters.
So welcome covenant children to Jesus Christ…