Luke
Luke 6:3ESV·traditional attribution

And Jesus answered them, “Have you not read what David did when he was hungry, he and those who were with him:

Matthew Henry Presbyterian @wholebiblehenry

These two passages of story we had both in Matthew and Mark, and they were there laid together (Mat 12:1; Mar 2:23; Mar 3:1), because, though happening at some distance of time from each other, both were designed to rectify the mistakes of the scribes and Pharisees concerning the sabbath day, on the bodily rest of which they laid greater stress and required greater strictness than the Law-giver intended.

Commenting on Luke 6:1-11

John Gill Reformed Baptist @doctorgill

And Jesus answering them, said,.... For they brought the charge against the disciples to him, being desirous to know what he would say, and that they might have something to accuse him of; and who, at once, took up the cause of his disciples, and vindicated them, by observing what David did, when he, and his men were an hungry; how that he went into...

Albert Barnes Presbyterian @notesbybarnes

Verse 3. No entry from BARNES for this verse. (c) "what David did" .