2 Samuel 3:35-37
35-37They all came then to David, trying to get him to eat something before dark. But David solemnly swore, "I'll not so much as taste a piece of bread, or anything else for that matter, before sunset, so help me God!" Everyone at the funeral took notice—and liked what they saw. In fact everything the king did was applauded by the people. It was clear to everyone that day, including all Israel, that the king had nothing to do with the death of Abner son of Ner.
38-39The king spoke to his servants: "You realize, don't you, that today a prince and hero fell victim of foul play in Israel? And I, though anointed king, was helpless to do anything about it. These sons of Zeruiah are too much for me. God, requite the criminal for his crime!"