David was thirsty {for some water from his home town}. So he said, "I wish someone could give me some water from that well near the city gate in Bethlehem." {David did not really want this, he was only talking.}
But the Three F122 fought their way through the Philistine army. These three men got some water from the well near the city gate in Bethlehem. Then the Three Heroes brought the water to David. But David refused to drink the water. He poured it out on the ground as an offering to the Lord.
David said, "God, I can't drink this water. It would be like drinking the blood of the men who risked their lives to get this water for me." That is why David refused to drink the water. The Three Heroes did many brave things like that.