Chapter on the Detailed Explanation of Prayer, Including the Obligatory and Recommended, and What is Permissible and Not Permissible.

And from him, from Ahmad ibn Muhammad, from Ibn Abi Nasr, from Aban ibn Uthman, from Abdur Rahman ibn Abi Abdullah, who said: I said to Abu Abdillah عليه السلام, peace be upon him: “A man raised his head from prostration and doubted before he became fully seated, not knowing whether he had prostrated or not.” Imam عليه السلام said: "He should prostrate." I asked: “And a man who rose from his prostration and doubted before he became fully standing, not knowing whether he had prostrated or not.” Imam عليه السلام said: "He should prostrate."