For dedicating of the altar. The altar was "dedicated" in the sense of being consecrated, by the anointing with the sacred oil and with the blood of the appointed sacrifices (Le Numbers 8:10, Numbers 8:15).
But it could still be "dedicated" in another sense by the sacrificial gifts, freely offered for the purpose, of the people. No rules appear to have been made as to dedications, but there is an allusion in Deuteronomy 20:5 to the dedication of houses, which may have been accompanied with religions rites, and we know that as a fact the temple was dedicated by Solomon (2 Chronicles 7:5), and re-dedicated by the Maccabees (1 Macc 4:54, sq.
), and the wall of Jerusalem was dedicated by Nehemiah (Nehemiah 12:27, sq.). The Septuagint has here εἰς τὸν ἐγκαινισμὸν, as in 1 Macc 4:56, and cf. John 10:22. Offered their offering before the altar.
This assuredly points to an offering made in common, and made at one time, via, on the day when the altar was anointed. It may be that the twelve princes all came for the purpose of making their offerings on that day, the day they would naturally choose for the purpose; but on account of the great number of other sacrifices, and the fewness of the priests, their offerings were postponed by the Divine command, and were actually received later.
Thus in will and in meaning the offerings were made "on the day" of the consecration, but were publicly and solemnly received at some subsequent time.