These two Sabbath scenes make a climax to the preceding paragraphs, in
which Jesus has asserted His right to brush aside Rabbinical
ordinances about eating with sinners and about fasting. Here He goes
much further, in claiming power over the divine ordinance of the
Sabbath. Formalists are moved to more holy horror by free handling of
forms than by heterodoxy as to principles. So we can understand how
the Pharisees' suspicions were exacerbated to murderous hate by these
two incidents. It is doubtful whether Mark puts them together because
they occurred together, or because they bear on the same subject. They
deal with the two classes of 'works' which later Christian theology
has recognised as legitimate exceptions to the law of the Sabbath
rest; namely, works of necessity and of mercy.

I. Whether we adopt the view that the disciples were clearing a path
through standing corn, or the simpler one, that they gathered the ears
of corn on the edge of a made path as they went, the point of the
Pharisees' objection was that they broke the Sabbath by plucking,
which was a kind of reaping. According to Luke, their breach of the
Rabbinical exposition of the law was an event more dreadful in the
eyes of these narrow pedants; for there was not only reaping, but the
analogue of winnowing and grinding, for the grains were rubbed in the
disciples' palms. What daring sin! What impious defiance of law! But
of what law? Not that of the Fourth Commandment, which simply forbade
'labour,' but that of the doctors' expositions of the commandment,
which expended miraculous ingenuity and hair-splitting on deciding
what was labour and what was not. The foundations of that astonishing
structure now found in the Talmud were, no doubt, laid before Christ.
This expansion of the prohibition, so as to take in such trifles as
plucking and rubbing a handful of heads of corn, has many parallels
there.