12 Then Solomon offered burnt offerings to Yahweh on the altar of Yahweh, which he had built before the porch,
*Minor differences ignored. Grouped by changes, with first version listed as example.
Then Solomon offered burnt offerings to the Lord,.... Meaning not barely at the time he rebuilt the above cities, for it was his constant practice:
on the altar of the Lord, which he had built before the porch; the brasen altar, which was at the entrance into the temple, within the court; of which see 2-Chronicles 4:1.
The sacrificial service in the new temple. Cf. 1-Kings 9:25, where it is merely briefly recorded that Solomon offered sacrifices three times a year on the altar built by him to the Lord. In our verses we have a detailed account of it. אז, at that time, scil. when the temple building had been finished and the temple dedicated (cf. 2-Chronicles 8:1), Solomon offered burnt-offerings upon the altar which he had built before the porch of the temple. He no longer now sacrifices upon the altar of the tabernacle at Gibeon, as in the beginning of his reign (2-Chronicles 1:3.).
*More commentary available at chapter level.