Ja'far bin Muhammad (may Allah have mercy on him) narrates from his father that Sayyidah Umm Kulthum bint Ali (may Allah be pleased with her) and her son Zayd (may Allah be pleased with him) both died on the same day, and it could not be known whose death came first. So neither did Sayyidah Umm Kulthum (may Allah be pleased with her) inherit from him, nor did Zayd (may Allah be pleased with him) inherit from Sayyidah Umm Kulthum (may Allah be pleased with her). And the people of Siffin were not made heirs of one another, and the people of al-Harrah were not made heirs of one another.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12254