The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wa'l-Adab)
Muslim :: Book 32 : Hadith 6360
Abu Musa reported that when any needy (person) came to Allah's Messenger (may peace be upon him) with a need he commanded him to his Companions, saying: Make a recommendation for him, and you would get the reward. Allah, however, gives the verdict through the tongue of His Apostle what He likes most.