Mustadrak al-Hakim — Hadith 7011

It is narrated from Mus'ab bin Abdullah al-Zubayri that he said: Sayyidah Zaynab (may Allah be pleased with her) was the eldest daughter of the Messenger of Allah (peace and blessings be upon him), and the cause of her death was this: when she set out from Makkah to emigrate to the Messenger of Allah (peace and blessings be upon him), Habbar bin al-Aswad and another man caught up with her. One of them pushed her, so she fell onto a rock. She was pregnant, so she miscarried and began to bleed. She remained continually in this pain until she died of this very ailment.