Those Who Said He Should Complete (The Prayers) Based Upon His Strongest Judgement Sunan Abi Dawud 1028
Translation
AbuUbaydah reported, on the authority of his father Abdullah (ibn Mas'ud), the Messenger of Allah (ﷺ) as saying
When you are in prayer and you doubt between three or four, and your strongest conviction is four, you should recite the tashahhud, then prostrate two prostrations while you are sitting before you give the salutation, then recite the tashahhud again, and then give the salutation.
Abu Dawud said: 'Abd al-Wahid narrated it from Khusaif and did not attribute it directly to the Prophet (ﷺ). Sufyan, Sharik, and Isra'il also agreed with 'Abd al-Wahid, but they differed regarding the wording of the tradition and did not narrate it with a continuous chain up to the Prophet (ﷺ).