I Chronicles 11:15-19

Now three of the thirty chief men went down to the rock to David, into the cave of Adullam; and the army of the Philistines encamped in the Valley of Rephaim. David was then in the stronghold, and the garrison of the Philistines was then in Bethlehem. And David said with longing, “Oh, that someone would give me a drink of water from the well of Bethlehem, which is by the gate!” So the three broke through the camp of the Philistines, drew water from the well of Bethlehem that was by the gate, and took it and brought it to David. Nevertheless David would not drink it, but poured it out to the LORD. And he said, “Far be it from me, O my God, that I should do this! Shall I drink the blood of these men who have put their lives in jeopardy? For at the risk of their lives they brought it.” Therefore he would not drink it. These things were done by the three mighty men.