The great high place; the most eminent and frequented, because there was the tabernacle and the altar of Moses, 1 Chronicles 16:39, 1 Chronicles 21:29 2 Chronicles 1:3,5,6, which possibly were placed upon a high or raised ground. A thousand burnt offerings did Solomon offer upon that altar; thereby showing his special respect to this above all other places, and by his example teaching and inviting all his people to do so.
Related Commentaries of 1 Kings 3:4
1 Kings 3:4
4 And the king went to Gibeon to sacrifice there; for that was the great high place: a thousand burnt offerings did Solomon offer upon that altar.