19 Then came the disciples to Jeshu by himself, and said to him, Why were we not able to heal him?
Matthew 17:19 Cross References - Etheridge
Mark 4:10
10 And when he was alone, they who were with him along with his twelve inquired of him [concerning] that parable.
Mark 9:28
28 But when Jeshu had gone into the house, his disciples inquired of him by themselves, Why could not we cast him out?