What is the ruling on rewarding a gift, and should it be done immediately or can it be delayed?

It is sunnah for the recipient of a gift to reciprocate it, based on the hadith narrated by Aisha (may Allah be pleased with her) that the Prophet (peace be upon him) used to accept gifts and reciprocate them. The Prophet (peace be upon him) encouraged rewarding those who do a favor or give a gift. If one cannot find something to reciprocate with, then they should supplicate for the giver. This reciprocation is not required immediately, but hastening to do good is better.