He set the laver. As directed in Exodus 40:7. For the position of the laver, see Exodus 30:18.
Moses and Aaron and his sons washed their hands. This is not a part of the narrative of what was done at this time, but a parenthetic statement of the purpose to which the laver was subsequently applied. On the importance attached to these ablutions, see Exodus 30:20, Exodus 30:21.