Matthew 12:8

After this He mentions another reason likewise; "For the Son of man," saith He, "is Lord of the Sabbath day;" speaking it of Himself. But Mark relates Him to have said this of our common nature also; for He said, "The Sabbath was made for man, not man for the Sabbath." Wherefore then was he punished that was gathering the sticks? Because if the laws were to be despised even at the beginning, of course they would scarcely be observed afterwards. For indeed the Sabbath did at the first confer many and great benefits; for instance, it made them gentle towards those of their household, and humane; it taught them God's providence and the creation, as Ezekiel saith; it trained them by degrees to abstain from wickedness, and disposed them to regard the things of the Spirit. For because they could not have borne it, if when He was giving the law for the Sabbath, He had said, "Do your good works on the Sabbath, but do not the works which are evil," therefore He restrained them from all alike for, "Ye must do nothing at all," saith He: and not even so were they kept in order. But He Himself, in the very act of giving the law of the Sabbath, did even therein darkly signify that He will have them refrain from the evil works only, by the saying, "Ye must do no work, except what shall be done for your life." And in the temple too all went on, and with more diligence and double toil. Thus even by the very shadow He was secretly opening unto them the truth. Did Christ then, it will be said, repeal a thing so highly profitable? Far from it; nay, He greatly enhanced it. For it was time for them to be trained in all things by the higher rules, and it was unnecessary that his hands should be bound, who was freed from wickedness, winged for all good works; or that men should hereby learn that God made all things; or that they should so be made gentle, who are called to imitate God's own love to mankind (for He saith, "Be ye merciful, as your Heavenly Father"); or that they should make one day a festival, who are commanded to keep a feast all their life long; ("For let us keep the feast," it is said, "not with old leaven, neither with leaven of malice and wickedness; but with unleavened bread of sincerity and truth"); as neither need they stand by an ark and a golden altar, who have the very Lord of all for their inmate, and in all things hold communion with Him; by prayer, and by oblation, and by scriptures, and by almsgiving, and by having Him within them. Lo now, why is any Sabbath required, by him who is always keeping the feast, whose conversation is in Heaven?

He calls Himself the Son of Man, and the meaning is, He whom ye suppose a mere man is God, the Lord of all creatures, and also of the sabbath, and He has therefore power to change the law after His pleasure, because He made it.