Charles Ellicott Commentary 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? And Jesus said unto them, Can the sons of the bridechamber fast, while the bridegroom is with them? as long as they have the bridegroom with them, they cannot fast. But the days will come, when the bridegroom shall be taken away from them, and then will they fast in that day. No man seweth a piece of undressed cloth on an old garment: else that which should fill it up taketh from it, the new from the old, and a worse rent is made. And no man putteth new wine into old wineskins; else the wine will burst the skins, and the wine perisheth, and the skins: but [they put] new wine into fresh wine-skins." — Mark 2:18-22 (ASV)

And the disciples of John... used to fast.—Better, were fasting. See Notes on Matthew 9:14-17. The only difference in detail between the two accounts is that in St. Matthew the disciples of John are more definitely specified as being the questioners.