2 Samuel 23:13-16

23:13 At the time of the harvest three of the thirty leaders went down to David at the cave of Adullam. A band of Philistines was camped in the valley of Rephaim. 23:14 David was in the stronghold at the time, while a Philistine garrison was in Bethlehem. 23:15 David was thirsty and said, “How I wish someone would give me some water to drink from the cistern in Bethlehem near the gate!” 23:16 So the three elite warriors broke through the Philistine forces and drew some water from the cistern in Bethlehem near the gate. They carried it back to David, but he refused to drink it. He poured it out as a drink offering to the Lord