The disciples weren’t “harvesting” on the Sabbath, they were eating lunch. It was clear that the Pharisees had distorted and lost the true purpose for the Sabbath: rest for souls.
BibleGateway: Luke 6:1-11 ESV Text: Luke 6:1-11 Luke 6:1–11 (Listen) Jesus Is Lord of the Sabbath 6:1 On a Sabbath,1 while he was going through the grainfields, his disciples plucked and ate some heads of grain, rubbing them in their hands. 2 But some of the Pharisees said, “Why are you doing what is not lawful to do on the Sabbath?” 3 And Jesus answered them, “Have you not read what David did when he was hungry, he and those who were with…