John Gill

And Jesus said unto them,.... Both to John's disciples and the Pharisees, can the children of the bride chamber fast, while the bridegroom is with them? Suggesting that he was the bridegroom, as John their master had called him, Joh 3:29, and that his disciples were the children of the bride chamber; and that it was very unsuitable for them, and very unreasonable to desire them to fast at such a time, and under such a character: wherefore the answer returned by Christ himself to the question is, as long as they have the bridegroom with them, they cannot fast: all which the Syriac version expresses by "no": see Gill on Mat 9:15.