Hadith 2277
A man from the Ansar whose name was Ziyad said: I asked Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him): What is your opinion, if all the wives of the Prophet (peace and blessings be upon him) pass away, would it be permissible for the Prophet (peace and blessings be upon him) to marry? He said: Yes, because Allah Almighty has permitted the category of women in this verse «﴿لَا يَحِلُّ لَكَ النِّسَاءُ ......﴾» [احزاب: 52/33] and has described its characteristic, and has stated that after this characteristic, no other women are lawful for you.
Hadith 2278
Lady Aisha (may Allah be pleased with her) said: Allah Almighty made it lawful before the death of the Messenger of Allah (peace and blessings be upon him) that he could marry any woman he wished.