Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) sent a marriage proposal to Sayyiduna Ali (may Allah be pleased with him), asking him to marry Umm Kulthum (may Allah be pleased with her) to him. Sayyiduna Ali (may Allah be pleased with him) said: She is still young. Sayyiduna Umar (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) say: "On the Day of Resurrection every tie and lineage will be cut off, except my lineage and my tie." And I would love for my lineage and tie also to be joined to the Prophet (peace and blessings be upon him). So Sayyiduna Ali (may Allah be pleased with him) said to Sayyiduna Hasan and Sayyiduna Husayn (may Allah be pleased with them both): Marry her to him. They both said: She is a woman who should be given the choice over herself. So Sayyiduna Ali (may Allah be pleased with him) stood up in anger. Sayyiduna Hasan (may Allah be pleased with him) held him back by his garment and said: O dear father! It is impossible to bear separation from you. The narrator says: So she was married to him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13660