14 When they got back to the crowd, a man approached Yeshua and knelt down in front of him, 15 saying, “Master, show mercy to my son, because he has seizures and isn’t well, often falling into the fire or the water. 16 I brought him to your apprentices, but they weren’t able to heal him.”

17 “Oh you unbelieving and depraved generation,” Yeshua answered, “how much longer will I have to be with you people? How much longer can I tolerate you people? Bring your son here to me.” 18 Then Yeshua rebuked the demon and it came out of the boy, who was healed that very hour.

19 Later, the apprentices went by themselves to Yeshua and asked him why they hadn’t been able to drive away the demon.

20 “It’s because your faith is so small,” he told them, “because I can assure you that if your faith was as big as a mustard seed, you’d be able to command a mountain to move, and it would move, and then there’d be nothing that you apprentices couldn’t do.”[ref]