2 Samuel 23:13-17

13Then three of the thirty chief men went down and came to David at harvest time in the cave of Adullam, while an army of Philistines was encamped in the Valley of Rephaim.

14David was then in the stronghold, and the garrison of the Philistines was then in Bethlehem.

15And David had a craving and said, “Oh that someone would give me water to drink from the well of Bethlehem, which is by the gate!”

16So the three mighty men broke through the camp of the Philistines, and drew water from the well of Bethlehem by the gate, and carried and brought it to David. But he would not drink it, but poured it out [in worship] to the Lord.

17And he said, “Far be it from me, O Lord, that I should drink this. [Is it not the same as] the blood of the men who went at the risk of their lives?” So he would not drink it. These things the three mighty men did.