Book 11, Number 3933:

Jabir b. 'Abdullah (Allah be pleased with him) reported: Allah's Apostle (may peace be upon him) and Abi Bakr (Allah be pleased with him) visited me on foot in Banu Salama, and found me unconscious. He (the Holy Prophet) called for water and performed ablution and sprinkled out of it (the water) over me. I felt relieved. I said: Allah's Messenger, what should I do with my property? And this verse was revealed:" Allah enjoins you concerning your children: for the male is equal of the portion of two females."