From Sahih Muslim (Hadith 2492):
Abdullah b. Abu Aufa said that it was the common practice of the Messenger of Allah (ﷺ) that when the people brought to him sadaqa he blessed them:O Allah, bless them. So when Abu Aufa brought to him Sadaqa he (the Holy Prophet) said: O Allah, bless, the posterity of Abu Aufa
Reference: Muslim 2492