Charles Ellicott Commentary Matthew 5:9

"Blessed are the peacemakers: for they shall be called sons of God." — Matthew 5:9 (ASV)

The peacemakers — Our version rightly distinguishes between the temper which is simply “peaceable” in itself (James 3:17) and this, the higher form of the same grace, acting energetically upon others. To be able to say with power to those who are bitter foes, Sirs, you are brethren (Acts 7:26), is nobler even than to strive, as much as lieth in us, to live peaceably with all men (Romans 12:18). Rightly does this beatitude follow that of the “pure in heart,” for it is the absence of all baseness and impurity that gives the power to make peace.

The children of God — Better, sons of God. The English version slightly obscures the connection between the promise and the character of Him who had been declared to be the Son of God in the truest and highest sense. The witness of sonship was not to be found in the ways the Tempter had suggested, but in the work of “making peace” between God and man, between Jew and Gentile, even at the price of shedding His own blood (Colossians 1:20). And those who are sharers in that work should, according to their capacity, “be called”—i.e., be, and be recognized as, sharers in that sonship.