Mustadrak al-Hakim — Hadith 4494

It is narrated from Yahya bin Abd al-Rahman bin Hatib that Sayyidah Aishah (may Allah be pleased with her) said: When Sayyidah Khadijah (may Allah be pleased with her) passed away, Khawlah bint Hakim came to the Messenger of Allah (peace and blessings be upon him) and said: "Will you not marry?" He (peace and blessings be upon him) asked: "Whom?" She said: "If you wish, a virgin, and if you wish, a widow (or divorcee)." He (peace and blessings be upon him) asked: "Who is the virgin and who is the widow?" She said: "As for the virgin, she is the daughter of the person most beloved to you of Allah's creation, Aishah bint Abi Bakr; and the widow is Sawdah bint Zam'ah."
This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.