Matthew 17:19

Then the disciples approached Jesus privately [and] said, {Why} were we not able to expel it?"

And when he was alone, those around him together with the twelve began asking him about the parables.

And [after] he had entered into the house, his disciples asked him privately, "Why were we not able to expel it?"

Treasury of Scripture Knowledge

Then came the disciples to Jesus apart, and said, Why could not we cast him out?

And when he was alone, those around him together with the twelve began asking him about the parables.

And [after] he had entered into the house, his disciples asked him privately, "Why were we not able to expel it?"