Matthew 12:4

εἰσῆλθεν, ἔφαγον, he entered, they ate. Mark has ἔφαγεν. Weiss explains the harsh change of subject by combination of apostolic source with Mark. The two verbs point to two offences against the law: entering a holy place, eating holy bread. The sin of the disciples was against a holy time. But the principle involved was the same = ceremonial rules may be overruled by higher considerations. ὃ οὐκ ἐξὸν ἦν. οὓς in Mark and Luke agreeing with ἄρτους, and here also in T. R., but ὃ doubtless the true reading; again presenting a problem in comparative exegesis (vide Weiss-Meyer). ὃ ought to mean “which thing it was not lawful to do,” but it may be rendered “which kind of bread,” etc. εἰ μὴ, except; absolutely unlawful, except in case of priests.