God: "I looked for someone to take a stand for me, and stand in the gap" (Ezekiel 22:30)
The rule is a positive command that we should treat others as we would wish them to treat us. The negative form is well known in Jewish literature and in pagan literature… Jesus is, therefore, not saying something new here, but it is significant that He stresses the positive form of the rule. The negative form is merely a rule of prudence: do not hurt other people lest they retaliate. The positive form is not prudential but absolute: this is how you are to treat others (positively), regardless of how they treat you. Jesus thus goes beyond the negative form, citing the rarer and more demanding form (I. Howard Marshall).