Shared ground
These verses present “altar rules” for the day the altar begins its service (v. 18). The stated purpose is practical and ritual: the altar must be readied so burnt offerings can be offered and blood can be applied to it.
The passage also names who is authorized to handle this first rite: “the priests, the Levites…of the seed of Zadok” (v. 19). A young bull is required as the purification offering for day one, and its blood is applied to specific parts of the altar (horns, ledge corners, and surrounding border) (v. 20). The text explicitly says this action “cleanses” the altar and “makes atonement for it” (v. 20). Finally, the bull’s remains are burned in a designated place outside the sanctuary (v. 21).
Where interpretation differs
Two main questions draw different readings.
First, what time span is meant by “in the day when they shall make it” (v. 18). Some take it as one calendar day: the first day of the sequence described in 43:18–27. Others read it more broadly as the inauguration period (“when it is set up for use”), with v. 18 introducing the whole set of rites.
Second, what it means to “make atonement for” an altar (v. 20). Some read this as removing ritual impurity connected with the altar’s newness or contact with human workmanship, so it can safely host holy offerings. Others emphasize a relational meaning: the rite formally brings the altar into an accepted, authorized status for approach to God, even though the altar itself is not a moral agent.
Why the disagreement exists
The wording allows more than one time-sense for “in the day,” and the altar is an unusual object for “atonement” language, which often concerns persons. That pushes interpreters to ask whether the phrase is mainly about cleansing, authorization, or both.
What this passage clearly contributes
Explicitly, it shows that in Ezekiel’s vision the altar is not treated as automatically ready for worship simply because it exists. It must be inaugurated by a specific rite, performed by an authorized priestly group, using blood applied to key altar points, with careful handling of the remains outside the sanctuary. The passage ties acceptable worship to ordered procedure and to the holiness of the sanctuary space, where even sacred equipment requires ritual preparation.