They asked this question to accuse the disciples of breaking the law. It can be written as a statement. Alternate translation: "Picking grain on the Sabbath is against God's law!" (See: [[rc://en/ta/man/translate/figs-rquestion]])
The Pharisees considered even the small action of rubbing a handful of grain to be unlawful work. This can be stated clearly. Alternate translation: "doing work" (See: [[rc://en/ta/man/translate/figs-explicit]])