Which of you shall have an ox or an ass? Though they did not deserve that Christ should take pains to remove the offense, yet he shows that he did nothing inconsistent with the observance of the Sabbath. And this he undoubtedly does, not so much with the view of instructing them, as of protecting himself against their slanders; for he knew that they were too much blinded by virulent hatred to yield submissively, to argument, but wished to triumph over their malice, by compelling them through shame to be silent. If we are at liberty to relieve brute animals on Sabbath, it would be unreasonable that we should not perform a similar office of kindness to man, who is formed after the image of God.

See the notes at Matthew 12:11.
Which of you - In this way Jesus refuted the notion of the Pharisees. If it was lawful to save an ox on the Sabbath, it was also to save the life of a man. To this the Jews had nothing to answer.

An ass or an ox - See on Luke 13:15 (note).

And answered them, saying,.... Murmuring secretly at what he had done:
which of you shall have an ass, or an ox fallen into a pit, and will not straightway pull him out on the sabbath day? being just ready to be drowned there; and therefore it must be much more right and necessary to cure a man, a reasonable creature, just drowning with a dropsy, as this man was. The Syriac and Persic versions, instead of "an ass", read "a son", very wrongly: a like kind of reasoning is used by Christ, in See Gill on Matthew 12:11, Luke 13:15.