'Aayeshah Radiyallahu 'Anha says that Rasulullah Sallallhu 'Alayhi Wasallam said:
"We have no heirs. What we (the ambiyaa) leave is sadaqah" (TR)
English reference (TR): Book 54, Hadith 385 (TR)
Arabic reference (TR): Book 55, Hadith 402 (TR)