Sayyidah Aishah (may Allah be pleased with her) said: Sayyiduna Abu Bakr (may Allah be pleased with him) died on the night of Tuesday, with eight nights remaining of Jumada al-Akhirah, in the year 13 AH. He left instructions that he be washed by Sayyidah Asma' bint Umays (may Allah be pleased with her), who was his wife; she had become weak, so Sayyiduna Abd al-Rahman bin Abi Bakr (may Allah be pleased with him) assisted her.
This connected (mawsul) hadith, its narrator being Muhammad bin Umar al-Waqidi, the author of the history and the Maghazi, is not strong. It has supporting mursal reports from Ibn Abi Mulaykah, and from Ata bin Abi Rabah from Sa'd bin Ibrahim, that Asma' bint Umays washed her husband Abu Bakr (may Allah be pleased with him), and some of them mentioned that Abu Bakr (may Allah be pleased with him) had instructed that.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6663