A. Yusuf Ali:Translation:
When a (courteous) greeting is offered you, meet it
with a greeting still more courteous, or (at least) of
equal courtesy. Allah takes careful account 605 of all
things.

Muhammad Asad:Translation:
But when you are greeted with a greeting [of peace], answer with an even better greeting, or [at least] with the like thereof. 105 Verily, God keeps count indeed of all things.
605 The necessary correlative to the command to fight in a good cause is the command to cultivate sweetness and cordiality in our manners at all times. For righting is an exceptional necessity while the sweetness of daily human intercourse is a normal need. Further, we give kindness and courtesy without asking, and return it if possible in even better terms than we received, or at least in equally courteous terms. For we are all creatures of One God, and shall be brought together before Him.