Matthew 9:14

Then the disciples of John came to him, saying, Why do we and the Pharisees frequently go without food, but your disciples do not?

Matthew 11:2

Now when John had news in prison of the works of the Christ, he sent his disciples

John 3:25

Then a question came up between John's disciples and a Jew about washing.

John 4:1

Now when it was clear to the Lord that word had come to the ears of the Pharisees that Jesus was making more disciples than John and was giving them baptism

Proverbs 20:6

Most men make no secret of their kind acts: but where is a man of good faith to be seen?

Matthew 6:16

And when you go without food, be not sad-faced as the false-hearted are. For they go about with changed looks, so that men may see that they are going without food. Truly I say to you, They have their reward.

Matthew 11:18-19

For John came, taking no food or drink, and they say, He has an evil spirit.

Mark 2:18-22

And John's disciples and the Pharisees were taking no food: and they came and said to him, Why do John's disciples and the disciples of the Pharisees go without food, but your disciples do not?

Luke 5:33-39

And they said to him, The disciples of John frequently go without food, and make prayers, and so do the disciples of the Pharisees; but your disciples take food and drink.

Luke 18:9-12

And he made this story for some people who were certain that they were good, and had a low opinion of others:

Treasury of Scripture Knowledge

Summary

Then came to him the disciples of John, saying, Why do we and the Pharisees fast oft, but thy disciples fast not?

Bible References

Why

Matthew 6:16
And when you go without food, be not sad-faced as the false-hearted are. For they go about with changed looks, so that men may see that they are going without food. Truly I say to you, They have their reward.
Matthew 11:18
For John came, taking no food or drink, and they say, He has an evil spirit.
Proverbs 20:6
Most men make no secret of their kind acts: but where is a man of good faith to be seen?
Mark 2:18
And John's disciples and the Pharisees were taking no food: and they came and said to him, Why do John's disciples and the disciples of the Pharisees go without food, but your disciples do not?
Luke 5:33
And they said to him, The disciples of John frequently go without food, and make prayers, and so do the disciples of the Pharisees; but your disciples take food and drink.
Luke 18:9
And he made this story for some people who were certain that they were good, and had a low opinion of others:

Basic English, produced by Mr C. K. Ogden of the Orthological Institute - public domain