There is a difference between the two stories that some may believe significant when making the comparison (i.e. David and his followers / Jesus and the disciples).  David actually deceives Ahim’elech into giving him the bread.  He told the priest he was on a secret mission from the king when, in fact, he was fleeing from Saul who had vowed to kill him.  In his hasty preparations to flee, David had not packed sufficient supplies.  While the lie does not come into play in the New Testament story, most commentators don’t view the difference between the two accounts as significant as the common theme of necessity.  Both David’s followers and Jesus’ disciples, in serving their masters, had grown sufficiently hungry in the course of their duties that their masters broke with the norm to feed them.

Lawful

Next Jesus weaves a lawful argument based on the requirements specified in the Book of Numbers (28:9-20).  In the Old Testament book, the prescription for the sabbath offering is described.  To me, it sounds a lot of like work:

…you shall offer a burnt offering to the LORD: two young bulls, one ram, seven male lambs a year old without blemish; also three tenths of an ephah of fine flour for a cereal offering, mixed with oil, for each bull; and two tenths of fine flour for a cereal offering, mixed with oil, for the one ram; and a tenth of fine flour mixed with oil as a cereal offering for every lamb; for a burnt offering of pleasing odor, an offering by fire to the LORD.

However, a few verses later in the text it says: “On the first day there shall be a holy convocation: you shall do no laborious work….”  The “first day” is the sabbath.  The Pharisees are chiding the disciples, not for stealing, but working (i.e. harvesting) on the sabbath.  The slaughtering of animals, a “laborious work,” is forbidden on the sabbath by everyone except the high priests.  Jesus calls the priests who worked on the sabbath, for the purpose of worship, “innocent.”  But how is that?  Isn’t there a disconnect here?  The implication is temple worship takes precedence over the sabbath.  Jesus makes the same connection; however, he takes it a step further when he says there is, “something greater than the temple here.”  If the Pharisees believe temple worship takes precedence over the sabbath, Jesus is saying there is even something greater than the temple.  It’s no wonder they believe Jesus to be a blasphemer.

Prophetical

The next way Jesus addresses the Pharisees objection is by referring to the prophet Hosea who spoke on behalf of the Lord, saying:

For I desire steadfast love and not sacrifice, the knowledge of God, rather than burnt offerings. (Hosea 6:6)

Jesus rebukes the Pharisees’ lack of understanding of the scripture by saying, “If you knew what this meant, I desire mercy, not sacrifice, you would not have condemned these innocent men.”  The implication here is that if the Pharisees truly knew the scriptures they would act accordingly (i.e. know that God desires good will towards mankind and act similarly).  Jesus refers to his disciples as “innocent men,” just like the priests who work on the sabbath were “innocent,” because both are working for something that is more significant than the sabbath.  The Pharisees were only concerned with outward projections of piety rather than the true spiritual significance of the words contained in scripture.

Reasonableness

The last part of Jesus’ rebuttal is based on reason.  Since he is the Lord of the sabbath his disciples, who are acting in union with him, had a right to do what would normally be considered objectionable to do on the sabbath.  This is an expansion, a revelation, of the idea expressed above: “something greater than the temple is here.”  Yes, there is!  The God-man is here!  The one who originally commanded what is right, good, and holy, on the sabbath is now, once again, declaring what is right, good, and holy on the sabbath.  It is not a canceling of one in lieu of the other; instead, it is a deeper dive into what is already known.

Though not part of today’s reading, the narrative in Matthew’s Gospel continues with Jesus healing a man on the sabbath and Jesus challenging the Pharisees with a predicament:

Which one of you who has a sheep that falls into a pit on the sabbath will not take hold of it and lift it out? (Mt 12:11)

Knowing that a reasonable, common sense approach to life would lead one to conclude that relieving a man’s suffering and rescuing an animal are more significant than abstaining from work on a particular day of the week, Jesus concludes with, “So it is lawful to do good on the sabbath.”  This strikes me as much as a statement of fact as it does a question to be posed to those who doubt otherwise.

Conclusion

Jesus shows in Matthew’s eighth chapter, through word and deed, that there are times when the rule needs to give way to the exception.  Jesus’ purpose was not to provide “an out” from observance of the sabbath, not at all.  In fact, in order for there to be “an exception” there must first be a “rule” (exceptio probat regulam in casibus non exceptis (“the exception confirms the rule in cases not excepted”).  Worship of the Lord on the sabbath is proper and right.  By regularly going to the synagogue to teach and by expressing his intense desire to celebrate the Passover with his disciples (cf. Luke 22:15), Jesus demonstrates a commitment to the rule (i.e. law).  However, these teachings in Matthew’s eighth chapter were designed by the Lord to give his disciples, and us, greater spiritual insight into the law’s meaning.