Jamieson, Fausset and Brown on 1 Kings 11:9-12

9-12. the Lord was angry with Solomon--The divine appearance, first at Gibeon [1Ki 3:5], and then at Jerusalem [1Ki 9:2], after the dedication of the temple, with the warnings given him on both occasions [1Ki 3:11-14; 9:3-9], had left Solomon inexcusable; and it was proper and necessary that on one who had been so signally favored with the gifts of Heaven, but who had grossly abused them, a terrible judgment should fall. The divine sentence was announced to him probably by Ahijah; but there was mercy mingled with judgment, in the circumstance, that it should not be inflicted on Solomon personally--and that a remnant of the kingdom should be spared--"for David's sake, and for Jerusalem's sake, which had been chosen" to put God's name there; not from a partial bias in favor of either, but that the divine promise might stand (2Sa 7:12-16).