Jesus answered their question with one that drew on a familiar wedding custom: no one mourns at a wedding while the bridegroom is present. Barnes explains that the bridegroom's special friends "do not think of fasting while he is with them. With them it is a time of festivity and rejoicing; and mourning would not be appropriate." By asking it, Jesus let them reach the answer themselves. Barnes also draws out the contrast with their own situation: John, their friend and teacher, was in captivity, so for them it was fitting to fast; Jesus was with His disciples, so "It is, with them, a time of joy."

Jesus answered His own question in the same breath: "but the days will come, when the bridegroom shall be taken from them, and then shall they fast" (Matthew 9:15). He then gave two pictures to show that the new does not fit old forms: new cloth on an old garment, and new wine in old bottles (Matthew 9:16-17). Matthew records no reply from John's disciples.

"Children of the bridechamber" translates the Greek huioi tou nymphonos, literally "sons of the bridechamber." Thayer defines them as "the friends of the bridegroom whose duty it was to provide and care for whatever pertained to the bridal chamber." The ESV calls them "wedding guests."

Gill notes a Jewish custom that freed the bridegroom, his friends, and "the children of the bride chamber" from certain religious duties, such as dwelling in booths at the feast of tabernacles and keeping the set times of prayer and phylacteries. He also quotes Maimonides, a medieval Jewish teacher, that "all fasts shall cease in the days of the Messiah," citing Zechariah 8:19. The Greek question begins with me, a word that expects the answer "no."

In this question Jesus speaks of Himself as the bridegroom. John the Baptist had already used this picture, calling himself "the friend of the bridegroom" who rejoices at His voice (John 3:29), and Gill points to that verse here. Jesus' presence turned the season from mourning to joy.

But the question also looks ahead to sorrow. "The bridegroom shall be taken from them" points to a coming loss. Gill takes this to mean Christ would be taken "in a forcible manner, and put to death, as he was." Even in a moment of joy, Jesus knew the way ahead and told His followers that sorrow would come, and with it a fitting time to fast.