Matthew 9:14

Then John's disciples came to Jesus, and asked: "Why do we and the Pharisees fast while your disciples do not?"

Matthew 11:2

Now John had heard in prison what the Christ was doing, and he sent a message by his disciples,

John 3:25

Now a discussion arose between some of John's disciples and a Jew on the subject of 'purification;'

John 4:1

Now, when the Master heard that the Pharisees had been told that he was making and baptizing more disciples than John

Matthew 6:16

And, when you fast, do not put on gloomy looks, as hypocrites do who disfigure their faces that they may be seen by men to be fasting. That, I tell you, is their reward!

Matthew 11:18-19

For, when John came, neither eating nor drinking, men said 'He has a demon in him';

Mark 2:18-22

Now John's disciples and the Pharisees were keeping a fast, and people came and asked Jesus: "Why is it that John's disciples and the disciples of the Pharisees fast, while yours do not?"

Luke 5:33-39

"John's disciples," they said to Jesus, "Often fast and say prayers, and so do the disciples of the Pharisees, while yours are eating and drinking!"

Luke 18:9-12

Another time, speaking to people who were satisfied that they were religious, and who regarded every one else with scorn, Jesus told this parable--

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 gloomy looks, as hypocrites do who disfigure their faces that they may be seen by men to be fasting. That, I tell you, is their reward!
Matthew 11:18
For, when John came, neither eating nor drinking, men said 'He has a demon in him';
Mark 2:18
Now John's disciples and the Pharisees were keeping a fast, and people came and asked Jesus: "Why is it that John's disciples and the disciples of the Pharisees fast, while yours do not?"
Luke 5:33
"John's disciples," they said to Jesus, "Often fast and say prayers, and so do the disciples of the Pharisees, while yours are eating and drinking!"
Luke 18:9
Another time, speaking to people who were satisfied that they were religious, and who regarded every one else with scorn, Jesus told this parable--