1356 — “If one of you becomes forgetful in his prayer and does not know whether he has prayed one rak‘ah or two, let him proceed on the basis of one. If he does not know whether he has prayed two or three, let him proceed on the basis of two. If he does not know whether he has prayed three or four, let him proceed on the basis of three, and let him perform two prostrations before giving the salām.”

Al-Tirmidhi (1/80–81), Ibn Majah (1209), al-Tahawi (1/251), al-Hakim (1/324–325), al-Bayhaqi (2/332), and Ahmad (1/190) recorded it through Muhammad ibn Ishaq, from Makhul, from Kurayb, from Ibn Abbas, from Abd al-Rahman ibn Awf, who said: “I heard the Prophet, peace and blessings be upon him, say…” He then cited it. The wording is al-Tirmidhi’s, and he said: “A good, singular, authentic hadith.”

That is what he said; yet Makhul and Ibn Ishaq both practised tadlīs, and both narrated it using an ambiguous transmission formula. So how can it be good, let alone authentic? Ibn Ishaq did explicitly state that he heard it in one version recorded by Ahmad (1/193), but he transmitted it mursal from Makhul and gave its connected chain by another route. Ahmad said: Isma‘il narrated to us: Muhammad ibn Ishaq narrated to me: Makhul narrated that the Messenger of Allah, peace and blessings be upon him, said: “When one of you prays and doubts in his prayer…” Ibn Ishaq said: Husayn ibn Abd Allah said to me, “Did he provide you with its connected chain?” I replied, “No.” He said, “But he told me that Kurayb, the freed slave of Ibn Abbas, narrated it to him from Ibn Abbas.”

Al-Bayhaqi likewise recorded it, and then remarked: “Thus, the connected chain of the hadith rests with Husayn ibn Abd Allah, who is weak; except that it has a supporting report from the hadith of Makhul”—meaning, from Kurayb through him. Then he and al-Hakim (1/324) recorded it through two routes from Abd al-Rahman ibn Thabit, from his father, from Makhul, in an abridged form, with the wording: