Albert Barnes Commentary Matthew 5:47

"And if ye salute your brethren only, what do ye more [than others?] do not even the Gentiles the same?" — Matthew 5:47 (ASV)

And if ye salute your brethren, etc. The word salute here means to show the customary tokens of civility, or to treat with the common marks of friendship. (See Barnes on Luke 10:4).

He says that the worst men, the very publicans, would do this. Christians should do more; they should show that they had a different spirit; they should treat their enemies as well as wicked men did their friends. This should be done:

1. Because it is right; it is the only really amiable spirit.
2. And we should show that religion is not selfish, and is superior to all other principles of action.