That which is not lawful. The supposed unlawfulness was not the plucking of the ears of corn with the hand, which was expressly permitted by the Law (Deuteronomy 23:25), but the plucking and eating on the sabbath day.
David … and they that were with him. This seems opposed to what we read in 1 Samuel 21:1-15., where David is stated to have been alone. But the facts appear to have been these, that David, fleeing from Saul, went alone to Ahimelech the high priest, and sought and obtained five loaves of the "shewbread," which he carried away with him to his companions in flight, and shared with them; for he says (1 Samuel 21:2), "I have appointed my servants to such and such a place." This incident actually happened in the high priesthood of Ahimelech the father of Abiathar. Bede says that they were both present when David came in his distress and obtained the shewbread. But Ahimelech having been slain, together with eighty-six priests, by Saul, Abiathar fled to David, and became his companion in his exile. Moreover, when he succeeded to the high priesthood on the death of Ahimelech, he did far more good service than his father had done, and so was worthy of being spoken of with this special commendation, and as though he was actually high priest, even though his father was then living. The words may properly mean "in the days when Abiathar was living who became high priest, and was more eminent than his father." The shewbread; literally, the bread of the face, that is, of the Divine presence, symbolizing the Divine Being who is the Bread of life. It was directed by the Law that within the sanctuary there should be a table of shittim (or acacia) wood; and every sabbath twelve newly baked loaves were placed upon it in two rows. These leaves were sprinkled with incense, and then remained there until the following sabbath. They were then replaced by twelve newly baked loaves, the old loaves being eaten by the priests in the holy place, from which it was unlawful to remove them. These twelve loaves corresponded to the twelve tribes. The force of our Lord's reasoning is this: David, a man after God's own heart, when sorely pressed by hunger, applied to the high priest and took some of these sacred loaves, loaves which under ordinary circumstances it was not lawful for the lay people to eat, because he wisely judged that a positive law, forbidding the laity to eat this bread, ought to yield to a law of necessity and of nature; which intimates to us that in a grave necessity of famine, life may be lawfully preserved by eating even sacred bread which has been dedicated to God. Therefore, in like manner, nay, much more, was it lawful for Christ and his disciples to pluck the ears of corn on the sabbath day, that by rubbing them in their hands they might pick out the good grain and satisfy their hunger.