Matthew 9:14

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

Matthew 11:2

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

John 3:25

Then there arose a question between some of John's disciples and the Jews about purifying.

John 4:1

When therefore the Lord knew how the Pharisees had heard that Jesus made and baptized more disciples than John,

Proverbs 20:6

Most men will proclaim everyone his own goodness: but a faithful man who can find?

Matthew 6:16

Moreover when you fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward.

Matthew 11:18-19

For John came neither eating nor drinking, and they say, He has a demon.

Mark 2:18-22

And the disciples of John and of the Pharisees used to fast: and they came and said unto him, Why do the disciples of John and of the Pharisees fast, but your disciples fast not?

Luke 5:33-39

And they said unto him, Why do the disciples of John fast often, and make prayers, and likewise the disciples of the Pharisees; but you eat and drink?

Luke 18:9-12

And he spoke this parable unto certain who trusted in themselves that they were righteous, and despised 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
Moreover when you fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may appear unto men to fast. Verily I say unto you, They have their reward.
Matthew 11:18
For John came neither eating nor drinking, and they say, He has a demon.
Proverbs 20:6
Most men will proclaim everyone his own goodness: but a faithful man who can find?
Mark 2:18
And the disciples of John and of the Pharisees used to fast: and they came and said unto him, Why do the disciples of John and of the Pharisees fast, but your disciples fast not?
Luke 5:33
And they said unto him, Why do the disciples of John fast often, and make prayers, and likewise the disciples of the Pharisees; but you eat and drink?
Luke 18:9
And he spoke this parable unto certain who trusted in themselves that they were righteous, and despised others: