Luke 5:35

But a time for this will come, when the Bridegroom has been taken away from them: then, at that time, they will fast."

Luke 17:22

Then, turning to His disciples, He said, "There will come a time when you will wish you could see a single one of the days of the Son of Man, but will not see one.

Matthew 6:17-18

But, whenever you fast, pour perfume on your hair and wash your face,

Luke 24:17-21

"What is the subject," He asked them, "on which you are talking so earnestly, as you walk?" And they stood still, looking full of sorrow.

John 12:8

For the poor you always have with you, but you have not me always."

John 13:33

Dear children, I am still with you a little longer. You will seek me, but, as I said to the Jews, 'Where I am going you cannot come,' so for the present I say to you.

John 14:3-4

And if I go and make ready a place for you, I will return and take you to be with me, that where I am you also may be.

John 16:4-7

But I have spoken these things to you in order that when the time for their accomplishment comes you may remember them, and may recollect that I told you. I did not, however, tell you all this at first, because I was still with you.

John 16:16-22

"A little while and you see me no more, and again a little while and you shall see me."

John 16:28

I came from the Father and have come into the world. Again I am leaving the world and am going to the Father."

John 17:11-13

I am now no longer in the world, but they are in the world and I am coming to Thee. "Holy Father, keep them true to Thy name--the name which Thou hast given me to bear--that they may be one, even as we are.

Acts 1:9

When He had said this, and while they were looking at Him, He was carried up, and a cloud closing beneath Him hid Him from their sight.

Acts 3:21

Heaven must receive Him until those times of which God has spoken from the earliest ages through the lips of His holy Prophets--the times of the reconstitution of all things.

Acts 13:2-3

While they were worshipping the Lord and fasting, the Holy Spirit said, "Set apart for Me, now at once, Barnabas and Saul, for the work to which I have called them."

Acts 14:23

And in every Church, after prayer and fasting, they selected Elders by show of hands, and commended them to the Lord on whom their faith rested.

1 Corinthians 7:5

Do not refuse one another, unless perhaps it is just for a time and by mutual consent, so that you may devote yourselves to prayer and may then associate again; lest the Adversary begin to tempt you because of your deficiency in self-control.

2 Corinthians 11:27

with labour and toil, with many a sleepless night, in hunger and thirst, in frequent fastings, in cold, and with insufficient clothing.

Treasury of Scripture Knowledge

Summary

But the days will come, when the bridegroom shall be taken away from them, and then shall they fast in those days.

Bible References

And

Matthew 6:17
But, whenever you fast, pour perfume on your hair and wash your face,
Acts 13:2
While they were worshipping the Lord and fasting, the Holy Spirit said, "Set apart for Me, now at once, Barnabas and Saul, for the work to which I have called them."
Acts 14:23
And in every Church, after prayer and fasting, they selected Elders by show of hands, and commended them to the Lord on whom their faith rested.
1 Corinthians 7:5
Do not refuse one another, unless perhaps it is just for a time and by mutual consent, so that you may devote yourselves to prayer and may then associate again; lest the Adversary begin to tempt you because of your deficiency in self-control.
2 Corinthians 11:27
with labour and toil, with many a sleepless night, in hunger and thirst, in frequent fastings, in cold, and with insufficient clothing.