Sunan Abi Dawud 1513
سنن أبي داود#1513SahihThawban, the client of Messenger of Allah (ﷺ) said:When the Prophet (ﷺ) finished the prayer, he asked forgiveness three times and said: "O Allah ....." The narrator then narrated the tradition like that of 'Aishah
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim (591)
In-book reference: 8:98