1 Kings 3:1-4

Now Solomon became a son-in-law to Pharaoh king of Egypt [and formed an alliance] by taking Pharaoh’s daughter [in marriage]. He brought her to the City of David [where she remained temporarily] until he had finished building his own house (palace) and the house of the LORD and the wall around Jerusalem. But [in the meantime] the people were still sacrificing [to God] on the high places (hilltops) [as the pagans did to their idols], for there was no [permanent] house yet built for the Name of the LORD. Now Solomon loved the LORD, walking [at first] in the statutes of David his father, except [for the fact that] he sacrificed and burned incense in the high places [ignoring the law that required all sacrifices to be offered at the tabernacle]. [Lev 17:3, 4] The king went to Gibeon [near Jerusalem, where the tabernacle and the bronze altar stood] to sacrifice there, for that was the great high place. Solomon offered a thousand burnt offerings on that altar.