Musnad Ahmad 33:74

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, and Hajjaj narrated to us, Shu‘bah informed us, he said: I heard Muhammad ibn al-Munkadir, he said: I heard Jabir ibn ‘Abd Allah, he said: "The Messenger of Allah (may Allah bless him and grant him peace) entered upon me while I was ill and not in my right mind." He said: "So he performed ablution, then he poured [water] over me – or he said: 'Pour [water] over him' – and I regained my senses. I said: 'No one inherits from me except a *kalalah* (a person with no direct heirs), so how is the inheritance?'" He said: "Then the verse of the obligatory shares was revealed."