ISB ~ Luke 6 v3
Have you not read:The question is intentionally sarcastic and would be taken as an insult by the well-educated Pharisees.
what David did:Jesus appeals to a scriptural precedent from 1 Sam 21:1-6.
• The legal exception once made for King David and his men to eat holy bread permits Jesus and his disciples to eat grain on the holy day of Sabbath. In both cases the strict regulations of the Torah were allowed to bend to meet a pressing need (hunger) and to serve the anointed king of Israel (David and Jesus).