2 Samuel 11:13-15

13And David invited him, and he ate and drank before him; and he made him drunk. And in the evening he went out to lie on his couch with the servants of his lord, but did not go down to his house.

14And it came to pass in the morning, that David wrote a letter to Joab, and sent it by Urijah.

15And he wrote in the letter saying, Set Urijah in the front of the thickest fight, and withdraw from him, that he may be smitten and die.