1 Kings 3:2

3:2 The people, however, were still sacrificing at the high places, because a temple had not yet been built for the Name of the Lord.

An intriguing scripture! Lord I pray for your revelation.

HIGH PLACES BEING IN USE HIS SACRIFICES AT GIBEON.
high places were altars erected on natural or artificial eminences, probably from the idea that men were brought nearer to the Deity. They had been used by the patriarchs, and had become so universal among the heathen that they were almost identified with idolatry. They were prohibited in the law (Leviticus 17:3,4,Deuteronomy 12:13,14, Jeremiah 7:31, Ezekiel 6:3,4, Hosea 10:8). But, so long as the tabernacle was migratory and the means for the national worship were merely provisional, the worship on those high places was tolerated. Hence, as accounting for their continuance, it is expressly stated (1 Kings 3:2) that God had not yet chosen a permanent and exclusive place for his worship. ~ Jamieson, Fausset, Brown Commentary Critical and Explanatoryon the Whole Bible