9 Blessed are the peacemakers,
for they will be called children of God.
9 Jesus' concern in this beatitude is not with the peaceful but with the "peacemakers." "Peace" is of constant concern in both OT and NT (e.g., Isa 52:7; Eph 2:11-22; Heb 12:14). The making of peace itself has messianic overtones (cf. "Prince of Peace" in Isa 9:6-7). Jesus does not limit the peacemaking to only one kind, and neither will his disciples. In the light of the Gospel, Jesus himself is the supreme peacemaker, making peace between God and us (Eph 2:15-17; Col 1:20) and among human beings. Our peacemaking will include the promulgation of that Gospel. It must also extend to seeking all kinds of reconciliation. Those who undertake this work are acknowledged as God's "sons". In the OT, Israel has the title "sons" (Dt 14:1; Hos 1:10). Now it belongs to the heirs of the kingdom who are especially equipped for peacemaking and so reflect something of the character of their heavenly Father.
12 So in everything, do to others what you would have them do to you, for this sums up the Law and the Prophets.
12 The word "therefore" probably refers to the entire body of the sermon (5:17-7:12), for here there is a second reference to "the Law and the Prophets" (see comment on 5:17); Jesus stresses that he has taught about the true direction in which the OT law points, i.e., the Golden Rule. This rule sums up the Law and the Prophets (cf. Ro 13:9). In the context of fulfilling the Scriptures, it provides a handy summary of the righteousness to be displayed in the kingdom (cf. 5:20).
The verb translated "sums up" (lit., "is") might properly be translated "fulfills," as in Ac 2:16. In the deepest sense, therefore, the rule is the Law and the Prophets in the same way as the kingdom is the fulfillment of all that the Law and the Prophets foretold.
31 Do to others as you would have them do to you.
The so-called Golden Rule is not unique to Jesus, for it appears in various forms in the ancient world. Leviticus 19:18 says to “love your neighbor as yourself.” The philosopher Seneca wrote: “Let us show our generosity in the same manner that we would with to have it bestowed on us.” The negative version appears in Tobit 4:15 (“And what you hate, do not do to anyone,” nrsv) and is also attributed to Rabbi Hillel, a near contemporary of Jesus: “What is hateful to you, do not do to anyone else; that is the whole Law, all else is commentary.”