Matthew 9:14

Then the disciples of John came up to him and said, "Why do we and the Pharisees fast a great deal, and your disciples do not fast?"

Matthew 11:2

Now when John heard in prison what the Christ was doing, he sent his disciples

John 3:25

Now a dispute arose between John's disciples and a Jew over the question of 'purification';

John 4:1

Now when the Lord learned that the Pharisees had heard of Jesus gaining and baptizing more disciples than John

Matthew 6:16

When you fast, do not look gloomy like the hypocrites, for they look woebegone to let men see they are fasting; I tell you truly, they do get their reward.

Matthew 11:18-19

For John has come neither eating nor drinking, and men say, 'He has a devil';

Mark 2:18-22

As the disciples of John and of the Pharisees were observing a fast, people came and asked him, "Why do John's disciples and the disciples of the Pharisees fast, and your disciples do not fast?"

Luke 5:33-39

They said to him, "The disciples of John fast frequently and offer prayers, as do the disciples of the Pharisees; but your adherents eat and drink."

Luke 18:9-12

He also told the following parable to certain persons who were sure of their own goodness and looked down upon everybody else.

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
When you fast, do not look gloomy like the hypocrites, for they look woebegone to let men see they are fasting; I tell you truly, they do get their reward.
Matthew 11:18
For John has come neither eating nor drinking, and men say, 'He has a devil';
Mark 2:18
As the disciples of John and of the Pharisees were observing a fast, people came and asked him, "Why do John's disciples and the disciples of the Pharisees fast, and your disciples do not fast?"
Luke 5:33
They said to him, "The disciples of John fast frequently and offer prayers, as do the disciples of the Pharisees; but your adherents eat and drink."
Luke 18:9
He also told the following parable to certain persons who were sure of their own goodness and looked down upon everybody else.