Matthew 11:2 KJV

Now when John had heard in the prison the works of Christ, he sent two of his disciples,
Matthew 11:2, King James Version

In context

1 And it came to pass, when Jesus had made an end of commanding his twelve disciples, he departed thence to teach and to preach in their cities.

2 Now when John had heard in the prison the works of Christ, he sent two of his disciples,

3 And said unto him, Art thou he that should come, or do we look for another?

Mark 6:17 For Herod himself had sent forth and laid hold upon John, and bound him in prison for Herodias’ sake, his brother Philip’s wife: for he had married her.
Matthew 14:3 For Herod had laid hold on John, and bound him, and put him in prison for Herodias’ sake, his brother Philip’s wife.