The laver was a large reservoir for the water that the priests used to wash with as they performed their duties. It stood between the brazen altar and the sanctuary. Its presence there symbolized the fact that cleansing is necessary after the making of atonement and before the enjoyment of fellowship with God.
"The necessity of daily cleansing on the part of those who are engaged even in the most holy service, and of all who would approach God, is so obvious as hardly to require comment. The body washed with pure water has for its counterpart the daily cleansing of the soul, without which no man may minister in the Divine presence [cf. John 13:10]."495
The "base"(v. 18) was probably not a pedestal but a smaller vessel used to draw as much water out of the laver as the priest might need to wash. The priests washed their feet as well as their hands (v. 21).
