18 And he was sore athirst, and called on the LORD, and said, Thou hast given this great deliverance into the hand of thy servant: and now shall I die for thirst, and fall into the hand of the uncircumcised?
And now he began to burn with thirst, and there was no water, and yet he had great need of it. Wherefore perceiving that there is nothing so easy for human strength, as not to be rendered difficult by the absence of Divine aid, he besought God not to lay to his charge that he had ascribed ought to himself, giving Him all the glory of the victory, by the words, "Thou hast given this great deliverance into the hand of Thy servant," and now help me, for lo, "I die of thirst", and thirst gives me over into the hand of those over whom Thou hast given me so great a triumph. Wherefore God in His mercy clave a hollow place in the jaw bone which Samson had cast aside, and a stream of water flowed from it, and Samson drank, and his spirit revived, and he called the place 'the invoking of the spring,' because by his suppliant prayers he made amends for his boast of victory, and thus two judgements were opportunely declared, the one that arrogance soon incurs offence, the other that without any offence humility gains reconciliation.
Although we had been dried up because of lack of the dew of God’s grace, we merited to be changed into fountains and rivers. At that time Samson prayed and a fountain issued from the jawbone. This fact is clearly fulfilled in us, for the Lord himself said, “He who believes in me, from within him there shall flow rivers of living water.”
In the relics of the saints the Lord Christ has provided us with saving fountains which in many ways pour out benefactions and gush with fragrant ointment. And let no one disbelieve. For, if by the will of God water poured out of the precipitous living rock in the desert, and for the thirsty Samson from the jawbone of an ass, is it unbelievable that fragrant ointment should flow from the relics of the martyrs? Certainly not, at least for such as know the power of God and the honor which the saints have from him.
[AD 397] Ambrose of Milan on Judges 15:18-19