출애굽기 30:18 해설: Rashi, Chizkuni, Sforno & Or HaChaim

כיור A LAVER — like a large pot with teats which discharged water by the way of their openings.

ועשית כיור, “you are to make a laver;” the reason why this vessel has not been mentioned earlier when the furnishings of the Tabernacle have been listed, is that the function of the laver was only as something preparatory for the performance of a commandment, not a commandment itself.

ועשית כיור, this is another vessel which has not been mentioned before with the other vessels that were part of the Tabernacle. The reason is that the basin was not instrumental in attracting the presence of the Shechinah to the Tabernacle. Its function was merely preparatory to the priests’ service in the Tabernacle.

וכנו — Understand this as the Targum renders it: בסיסה ITS BASE, i. e. a stand specially made for the laver.