As he was passing through a field of grain on the sabbath, his disciples began to make a path while picking the heads of grain. At this the Pharisees said to him, "Look, why are they doing what is unlawful on the sabbath?" He said to them, "Have you never read what David did when he was in need and he and his companions were hungry? How he went into the house of God when Abiathar was high priest and ate the bread of offering that only the priests could lawfully eat, and shared it with his companions?" Then he said to them, "The sabbath was made for man, not man for the sabbath. That is why the Son of Man is lord even of the sabbath." (Mk 2:23-28)
Sabbath day was practiced among the Jews and it was to keep the day holy. God the creator rested on the seventh day from works of creation. In respect for God way of functioning and to observe the day from any creative works the Jews practiced the Sabbath rules. Any work that was revealing the act of creation or the beginning or making something new was forbidden. They would not light fire (it is creating light); they would not stitch (that would be equal to making a new garment); and they would not prepare food.
Jesus is aware of the practice and also he knows how David broke the rules of the offering and gave importance to the persons. Have you never read what David did?: Jesus defends the action of his disciples on the basis of 1 Sam 21:2-7 in which an exception is made to the regulation of Lev 24:9 because of the extreme hunger of David and his men.
Ritual observances must give way to moral obligations; and that may be done in a case of necessity. Man was created in the image and likeness of God and he was to have relationship with God and man was created to communicate God to the world. Man was not created tor the rules.
