A man came to the Prophet ﷺ and said, "Messenger of Allah, I prayed but I do not know whether I prayed an even or an odd number of rakahs."The Messenger of Allah ﷺ replied, "Beware of letting Satan toy with you in your prayer. Whoever among you prays and does not know whether he prayed an even or an odd number, let him perform two prostrations, for they will complete his prayer."
جاء رجل إلى النبي ﷺ فقال: يا رسول الله! إني صليت فلم أدر أشفعت أم أوترت؟ فقال رسول الله ﷺ: إياي، وأن يتلعب بكم الشيطان في صلاتكم، من صلى منكم فلم يدر أشفع أو أوتر، فليسجد سجدتين، فإنهما تمام صلاته.
Imam Ahmad narrated it (450) from Muhammad bin Abdullah bin Zubayr, who said, Musarra bin Mabad narrated to us, from Yazid bin Abu Kabsha, from Uthman bin Affan, and he mentioned something similar.In the chain is Musarra bin Mabad Lakhmi Filastini Maqdisi, of whom Abu Hatim said, "A shaykh, there is nothing wrong with him," and the hadith of someone like him is graded hasan.His teacher Yazid bin Abu Kabsha Saksaki was well known in his time. Bukhari said, "He was the chief of the Sakasik." Haytham bin Adi and Mujalid bin Saeed mentioned him among those who governed the two Iraqs. He is mentioned in Sahih Bukhari, in the Book of Jihad (2996), where Ibrahim Abu Ismail Saksaki said, "I heard Abu Burda," and he and Yazid bin Abu Kabsha traveled together on a journey. Yazid used to fast while traveling, so Abu Burda said to him, "I heard Abu Musa say many times, the Messenger of Allah said, 'When a servant falls ill or travels, it is recorded for him the same as what he used to do when settled and healthy.'"It appears from this that the man was of praiseworthy conduct. He is mentioned in the books of hadith and history, and we did not find in them anyone who spoke ill of him. Ibn Hibban mentioned him in Thiqat, so the hadith of someone like him is graded hasan. As for the Hafiz, he placed him at the rank of "acceptable," following his own rule, which is that everyone whom Ibn Hibban deemed trustworthy, and no one else deemed trustworthy, is "acceptable" in his view.But there is a break in the chain, for Ibn Abu Kabsha did not hear directly from Uthman, since between them stands Marwan bin Hakam, as narrated by Abdullah bin Ahmad (451) from Yahya bin Main and Ziyad bin Ayub, who both said, Sawwar Abu Umara Ramli narrated to us, from Musarra bin Mabad, who said, Yazid bin Abu Kabsha led us in the Asr prayer.Then he turned to us after his prayer and said, "I prayed with Marwan bin Hakam, and he prostrated just like these two prostrations." Then he turned to us and informed us that he had prayed with Uthman, and he narrated from the Prophet, mentioning something similar to that. So Sawwar bin Umara, or Sawwar Abu Umara, established this chain, and he is trustworthy. Nasai said of him, "There is nothing wrong with him."This hadith of Uthman, like the hadith of Abu Hurairah, is general in wording, and it is explained by the hadith of Abu Saeed Khudri.