Matthew 9:14

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

Matthew 11:2

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

John 3:25

There arose therefore a questioning on the part of John's disciples with a Jew about purifying.

John 4:1

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

Proverbs 20:6

Most men will proclaim every one his own kindness; But a faithful man who can find?

Matthew 6:16

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

Matthew 11:18-19

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

Mark 2:18-22

And John's disciples and the Pharisees were fasting: and they come and say unto him, Why do John's disciples and the disciples of the Pharisees fast, but thy disciples fast not?

Luke 5:33-39

And they said unto him, The disciples of John fast often, and make supplications; likewise also the disciples of the Pharisees; but thine eat and drink.

Luke 18:9-12

And he spake also this parable unto certain who trusted in themselves that they were righteous, and set all others at nought:

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 ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may be seen of men to fast. Verily I say unto you, They have received their reward.
Matthew 11:18
For John came neither eating nor drinking, and they say, He hath a demon.
Proverbs 20:6
Most men will proclaim every one his own kindness; But a faithful man who can find?
Mark 2:18
And John's disciples and the Pharisees were fasting: and they come and say unto him, Why do John's disciples and the disciples of the Pharisees fast, but thy disciples fast not?
Luke 5:33
And they said unto him, The disciples of John fast often, and make supplications; likewise also the disciples of the Pharisees; but thine eat and drink.
Luke 18:9
And he spake also this parable unto certain who trusted in themselves that they were righteous, and set all others at nought:

American Standard Version Public Domain