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 of the works of the Christ, he sent two of his disciples,

John 3:25

There arose, therefore, a dispute between some of John's disciples and a Jew, about purification.

John 4:1

When, therefore, the Lord knew that the Pharisees had heard that Jesus was making and immersing more disciples than John,

Matthew 6:16

And when you fast, do not put on a sad countenance, as the hypocrites do; for they disfigure their faces, that they may appear to men to be fasting. Verily, I say to 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 were in the habit of fasting; and they came, and said to him: Why do the disciples of John and of the Pharisees fast, but your disciples fast not?

Luke 5:33-39

And they said to him: Why do the disciples of John fast often, and make prayers, and likewise the disciples of the Pharisees, but yours eat and drink?

Luke 18:9-12

And he spoke this parable to some, who trusted in themselves that they were righteous, and who 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
And when you fast, do not put on a sad countenance, as the hypocrites do; for they disfigure their faces, that they may appear to men to be fasting. Verily, I say to you, They have their reward.
Matthew 11:18
For John came, neither eating nor drinking, and they say: He has a demon.
Mark 2:18
And the disciples of John and of the Pharisees were in the habit of fasting; and they came, and said to him: Why do the disciples of John and of the Pharisees fast, but your disciples fast not?
Luke 5:33
And they said to him: Why do the disciples of John fast often, and make prayers, and likewise the disciples of the Pharisees, but yours eat and drink?
Luke 18:9
And he spoke this parable to some, who trusted in themselves that they were righteous, and who despised others.