30 And he set the laver between the tent of the congregation and the altar, and put water there, to wash withal.
31 And Moses and Aaron and his sons washed their hands and their feet thereat:
32 When they went into the tent of the congregation, and when they came near unto the altar, they washed; as the Lord commanded Moses.
33 And he reared up the court round about the tabernacle and the altar, and set up the hanging of the court gate. So Moses finished the work.
The final element of the physical structure of the tabernacle was the water basin, which led directly to the preparation of the men who would serve there as priests. Interestingly, not only Aaron and his sons washed their hands and feet, but also Moses. Similarly, we heard in yesterday’s verses that he offered the first offerings upon the golden and brazen altars. Moving forward, we do not hear of him continuing to function in the role of the priest, but it seems that in this first instance he did.
My assumption is that Moses performed these rituals as the first priest, so that he could then transfer that authority and responsibility to Aaron and his sons. As has been previously discussed, it was as if Moses were the Lord, Himself. He was God’s approved representative, so he alone he was authorized to function in these sacred rituals. But after having once functioned in that role, and thus claimed them, he could then pass them on to others that the Lord had chosen: Aaron and his sons.
This idea is echoed by what verse 33 states: that “Moses finished the work.” Obviously, many hands were involved in the labor of creating the tabernacle, but all of them were only able to perform this service as an extension of Moses, who was the extension of God, Himself. Everything was fulfilled under the stewardship of Moses, and now he could hand its continuation to those who would remain after he was gone.