Matthew 17:15

17:15 and said, “Lord, have mercy on my son, because he has seizures ¹  and suffers terribly, for he often falls into the fire and into the water.

Mark 9:22

9:22 It has often thrown him into fire or water to destroy him. But if you are able to do anything, have compassion on us and help us.”

Luke 17:13

17:13 raised their voices and said, “Jesus, Master, have mercy ²  on us.”

[17:15]  ¹ tn Grk “he is moonstruck,” possibly meaning “lunatic” (so NAB, NASB), although now the term is generally regarded as referring to some sort of seizure disorder such as epilepsy (L&N 23.169; BDAG 919 s.v. σεληνιάζομαι).

[17:13]  ² sn “Have mercy on us” is a request to heal them (Luke 18:38-39; 16:24; Matt 9:27; 15:22; 17:15; 20:31-32; Mark 10:47-49).