John Gill Commentary Mark 2:20

"But the days will come, when the bridegroom shall be taken away from them, and then will they fast in that day." — Mark 2:20 (ASV)

But the days will come when the bridegroom shall be taken away from them, and then shallthey fast in those days : As they were in some sense now come to the disciples of John, their master being taken up by Herod, and confined in prison, and so it was a mourning time with them: referring to the time of the sufferings and death of Christ, which would be, and was a sorrowful season to his disciples.