One Sabbath day the disciples were hungry, so Jesus went through some corn fields so they could eat. (Mt 12:1) This was part of God’s social safety net (De 23:25), but the Pharisees began accusing them of breaking the Sabbath, looking for a way to find fault. (2)
In reply, Christ asks the Pharisees what they thought of David eating the shewbread as he was escaping from Saul (3-4), something they’d never allow. Why hadn’t God called David out on this? And why had God commanded the priests to continue their priestly duties on the Sabbath, something the Pharisees would consider profane in others? (5)
Christ concludes by noting that He’s greater than the temple (6), as reality is greater than its shadow (Col 2:17), and also Master of Sabbath, being its Author and knowing perfectly well how to apply it. (8)
Further, Christ declares the disciples formally innocent; they’d not actually broken Sabbath at all, only burdensome Pharisaical extrapolations of sabbatarian precepts, and identifies the root cause of the Pharisees’ error in their ignorance of a very basic principle of Torah: God prefers a merciful heart to being overly scrupulous in judging how well others are complying with Torah as they struggle and suffer. (7)
If the Pharisees had honored the spirit of Torah, loving mercy and humility as well as justice (Mi 6:8), they’d not have been adding burdensome regulations to Torah, and passing off their man-made doctrine as if it were God’s. (Mt 15:9)
Since activity required of the priests on sabbath is holy by definition, not sinful, they might only be said to “profane” the sabbath according to some misguided extrapolation of sabbath-related principles. This is evidently what the Pharisees were doing with the disciples as well, classifying plucking ears of corn as “work,” harvesting or reaping, thus forbidden on Sabbath, which was ridiculous.
In this context, Christ’s appeal to David’s example is interesting, for if it is actually sinful, a formal violation of Torah, then it is unique in this context. Perhaps Christ is pointing out that if God is lenient in overlooking certain ceremonial Torah violations for the alleviation of innocent human suffering, He is certainly not going to be overly restrictive in defining work when this augments the suffering of the needy, as the Pharisees had done.
However, it might well have been that David’s eating the shewbread was not actually forbidden per Torah itself, only a violation of Pharisaical interpretation. David identifies the bread as “in a manner common ” (1Sa 21:5), or in other words “not quite so holy.” Perhaps the shewbread was only forbidden to eat when it was still on the table in the tabernacle, and available within reason to those in need once it had been replaced by fresh bread and removed from the tabernacle. (vs 6)