Jesus wanted His hearers to see that loving only those who love you is nothing special. His first question asks what credit such love deserves. Barnes suggests "reward" here is used in the sense of deserving praise: love that only returns love is love for the benefit, and deserves no commendation. His second question points to the publicans, the tax collectors most despised by the Jews. Gill says even they, "by the very dictates of nature," loved those who loved them. Together the questions press the hearers to ask whether their love goes any further than that.

The answers are plain. Love that only returns love earns no special reward, and yes, even the publicans do the same. Jesus adds a second pair of questions about greeting only one's brethren (Matthew 5:47), and then gives the conclusion: "Be ye therefore perfect, even as your Father which is in heaven is perfect" (Matthew 5:48). The standard is not what others do, but what the Father does.

Publicans (Greek telonai) were tax collectors. Gill calls them "men of the worst characters, and who were most hateful to the Jews," partly because they collected taxes for the Romans. Barnes adds that the Jews ranked them with "thieves, and adulterers." To say "even the publicans" do something was to say anyone could do it.

The word "reward" is misthos, which means wages or pay. Jesus had already promised a "great" reward in heaven to those persecuted for His sake (Matthew 5:12). Here He asks what reward could be expected for love that costs nothing.

This question is rooted in God's own character. Jesus grounds the command to love enemies in what the Father does: "he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust" (Matthew 5:45). God's kindness reaches people who do not love Him back. His children are called to love the same way.

The question raises the bar on purpose. Matthew Henry writes, "Surely more is to be expected from the followers of Christ than from others." Jesus is not saying ordinary love for family and friends is wrong. He is saying it is not enough to mark someone as a child of the Father (Matthew 5:45, 48).