Matthew 17:19-21 Then the disciples came to Jesus privately, and said: Why were we not able to cast him out?

Anderson⁽ⁱ⁾ ¹⁹ Then the disciples came to Jesus privately, and said: Why were we not able to cast him out? ²⁰ And Jesus said to them: Because of your unbelief. For verily I say to you, If you have faith like a grain of mustard-seed, you shall say to this mountain, Be removed from this place to that, and it shall be removed: and nothing shall be impossible for you. ²¹ But this kind does not go out but by prayer and fasting.