What is the meaning of Matthew 17:15?

* The two F.O.G. Bibles & Commentary below are currently a work in progress.

“Lord, have mercy on my son,” he said. “He has seizures and is suffering terribly. He often falls into the fire or into the water.

Berean Standard Bible (BSB)

“Lord, have mercy on my son, for he is epileptic, and suffers grievously; for he often falls into the fire, and often into the water.

World English Bible (WEB)

Lord{G2962}, have mercy{G1653}{(G5657)} on my{G3450} son{G5207}: for{G3754} he is lunatick{G4583}{(G5736)}, and{G2532} sore{G2560} vexed{G3958}{(G5719)}: for{G1063} ofttimes{G4178} he falleth{G4098}{(G5719)} into{G1519} the fire{G4442}, and{G2532} oft{G4178} into{G1519} the water{G5204}.

Strong's King James

(15) "Adonai (LORD) have mercy on my son, for he's moonstruck (a lunatic) and suffers severely because he often falls down into the fire and the water!

The F.O.G*

[15] "Lord, please have mercy on my son!" he pleaded. "He suffers from severe seizures that often throw him into fire or water. His condition is destroying him!

The F.O.G Paraphrase

and saying, ‘Sir, deal kindly with my son, for he is lunatic, and doth suffer miserably, for often he doth fall into the fire, and often into the water,

Young's Literal Translation