1 Kings 3:2 - Joseph Benson’s Commentary on the Old and New Testaments

Only the people sacrificed in high places Which were groves, or other convenient places upon hills. In such places the patriarchs had been wont to offer up their worship, and sacrifices to God; and from them this custom was derived both to the Gentiles and the Jews; and in them the Gentiles sacrificed to idols, and the Hebrews to the true God. But this custom was expressly forbidden by God to his people, except in some extraordinary cases, and they were commanded to offer their sacrifices and other oblations only in the place which the Lord should choose, and where his tabernacle, altar, and ark should be, Leviticus 17:3-5; Deuteronomy 12:10-14. It is, therefore, here mentioned as an exception to Solomon's integrity and glory, and the happiness of his reign, and as a blemish to his government, that he permitted and practised what was thus so expressly forbidden. Possibly he permitted it because he thought it better to allow of an error in a circumstance, than occasion a neglect of God's worship altogether, which he apprehended would follow upon a severe prohibition of that practice. For the people's hearts were generally and constantly set upon these high places, as appears from the following history; and they were not willing to submit to the trouble and charge which the bringing their sacrifices to one place would cause, nor, indeed, would they yield to it until the temple was built: and, as that was speedily to be done, Solomon seems to have thought it more advisable to delay enforcing obedience to God's law in this point for the present, than by force to drive them to it. These, however, and all other prudential considerations, ought to have given place to the will and wisdom of God. Because there was no house built to the name of the Lord For his service, and to the honour, and praise, and glory of his name; that is, of his majesty, and all his perfections, which were to be adored and manifested there. But this reason for their sacrificing in high places was not sufficient; because there was a tabernacle, to which they were as much confined as they were afterward to the temple.