Jamieson, Fausset and Brown on 2 Samuel 11:9

9. But Uriah slept at the door of the king's house--It is customary for servants to sleep in the porch or long gallery; and the guards of the Hebrew king did the same. Whatever his secret suspicions might have been, Uriah's refusal to indulge in the enjoyment of domestic pleasure, and his determination to sleep "at the door of the king's house," arose from a high and honorable sense of military duty and propriety (2Sa 11:11). But, doubtless, the resolution of Uriah was overruled by that Providence which brings good out of evil, and which has recorded this sad episode for the warning of the church.

2Sa 11:14-27. Uriah Slain.