Salih bin Muhammad narrates: I heard Abdullah bin Umar bin Aban al-Ju'fi say that his maternal uncle Husayn al-Ju'fi asked him: O my son! Do you know why Sayyiduna Uthman (may Allah be pleased with him) is called Dhu al-Nurayn ("the one with two lights")? I said that I did not, so he said: From the creation of the earth and the heavens until the Day of Resurrection, Allah Almighty has not brought together two daughters of a prophet for anyone except Sayyiduna Uthman bin Affan (may Allah be pleased with him); that is why he is called Dhu al-Nurayn. Imam al-Shafi'i (may Allah have mercy on him) said: Zaynab bint Umm Salamah (may Allah be pleased with her) married Abdullah bin Zam'ah (may Allah be pleased with him), al-Zubayr bin al-Awwam (may Allah be pleased with him) married Asma' bint Abi Bakr (may Allah be pleased with her), and Sayyiduna Talhah (may Allah be pleased with him) married his other daughter, and both of them are sisters of the Mother of the Believers; and Abd al-Rahman bin Awf (may Allah be pleased with him) married the daughter of Jahsh, and she too is a sister of the Mother of the Believers. From all these proofs it is established that "the wives of the Prophet (peace and blessings be upon him) are the mothers of the believers" [Surah al-Ahzab: 6], yet the daughters of these mothers will not be their sisters, nor will their sisters become their maternal aunts.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13427