What does Judges 15:19 mean?

That Samson did not die in this incident is truly miraculous. Empowered by God's Spirit, he wiped out an entire Philistine army with nothing more than the jawbone of a donkey. It's not surprising that he'd be intensely thirsty after such an ordeal—so much so that he thought he'd die. That led to Samson's first recorded prayer, though it was demanding and accusatory towards God (Judges 15:14–18). That said, Samson at least gave the Lord credit for the victory and humbled himself just enough to make the request.

The Lord responds to Samson's request immediately. He splits open a nearby rock, which gushes water. Samson drinks and is revived. God graciously gives Samson what he asks, despite Samson's pride and selfishness.

The new spring is later called "En-hakkore," which literally means "the spring of him who called." The Bible does not explicitly say if Samson decided on this name. His initial celebration of victory was self-centered, so it wouldn't be shocking to know he'd named the location of this miracle after himself. Those in Israel reading this book closer to the time of Samson would likely have known about the spring at the place called Lehi. The term Lehi, itself, means "jawbone," likely a name given because of the events of this chapter.