Returning a supplication after having bestowed a gift or charity upon someone

وَفِيكَ بَارَكَ اللَّهُ ⁽¹⁾.

AAaishah رضي الله عنها reported that the Messenger of Allah (Peace Be Upon Him) was given a sheep and he ordered for it’s distribution. When the servant would come back (from distributing it), AAaishah would ask: ‘What did they say?’, he replied: They would supplicate: Barakal-lahu feekum.
‘May Allah bless you all.’ …AAaishah would then say: Wafeehim barakal-lah. ‘and may Allah bless them.’ …we return their supplication in a similar way and our reward remains with us.