Verse 28. - Therefore the Son of man is Lord also of the sabbath. "The sabbath was made for man." It is the inferior institution, man being the higher, for whose sake the sabbath was appointed. But the Son of man is Lord of all men, and of all things that pertain to man's salvation; therefore he must of necessity be Lord even of the sabbath; so that when he sees fit he can relax or dispense with its obligations. It is true that for us Christians the first day of the week, the Lord's day, has taken the place of the ancient Jewish sabbath; but the principle here laid down by our Lord is applicable to the "first" day no less than to the "seventh;" and it teaches us that our own moral and religious advancement and that of our brethren is the object which we should all aim at in the manner of our observance of the Christian Sunday; while we strive to "stand fast in the liberty wherewith Christ has made us free."
2:23-28 The sabbath is a sacred and Divine institution; a privilege and benefit, not a task and drudgery. God never designed it to be a burden to us, therefore we must not make it so to ourselves. The sabbath was instituted for the good of mankind, as living in society, having many wants and troubles, preparing for a state of happiness or misery. Man was not made for the sabbath, as if his keeping it could be of service to God, nor was he commanded to keep it outward observances to his real hurt. Every observance respecting it, is to be interpreted by the rule of mercy.
Therefore the son of man is Lord also of the sabbath. Meaning himself, who had a power not only to dispense with it, but to abrogate it as he did, with the rest of the rituals of the ceremonial law; See Gill on Matthew 12:8. So that it did not become them to find fault with what his disciples did, with his leave and approbation.