Abu Dawud Book 13, Hadith Number 2967.

Narated By AbuBakr : AbutTufayl said: Fatimah came to AbuBakr asking him for the inheritance of the Prophet (PBUH). AbuBakr said: I heard the Apostle of Allah (PBUH) say: If Allah, Most High, gives a Prophet some means of sustenance, that goes to his successor.