They shall purge the altar. Smend thinks it strange that only the purification of the altar should be mentioned here, while that of the sanctuary is referred to later (Ezekiel 45:18), and finds in this an explanation (at least, perhaps) of the fact that in Exodus 29:36 only the consecration of the Mosaic altar—not of the Mosaic tabernacle—is reported.
He conceives it likely that the author of Exodus 29:36 copied Ezekiel, but does not explain why Ezekiel may not have copied the author of Exodus 29:36. And they shall consecrate themselves; more correctly, they—i.
e. the priests—shall consecrate it; literally, fill its hand. The phrase, מִלֵּאיָד, "to fill one's hand," sc. with gifts, occurs with reference to Jehovah (Exodus 32:29; 1 Chronicles 29:5; 2 Chronicles 29:31).
It is also employed in the sense of filling the hand of another, as e.g. of a priest, with sacrificial gifts, when he is instituted into his sacred office (Exodus 28:41; Exodus 29:9; Le Exodus 21:10; comp, Le Exodus 8:27).
Here the hand to be filled is that of the altar, which is personified for the purpose (compare the use of the terms "bosom" and "lip" in connection with the altar). The meaning is that the altar, at its consecration, should have a plentiful supply of gifts, to symbolize that the offering of such gifts was the work for which it was set apart, and that it should never be without them.