John Chrysostom wrote: “Did Christ then attempt to repeal a law so beneficial as the sabbath law? Far from it. Rather, he greatly magnified the sabbath. For with Christ came the time for everyone to be trained by a higher requirement” (Homilies on the Gospel of St. Matthew, 39.3). In Christ we know that mercy and justice, biblically defined, must guide how we apply the letter of the Law. We are as bad as the Pharisees if we ignore these principles.
For further study:
The Bible in a year: