And what was narrated by Muhammad ibn Yaqub from Ali ibn Ibrahim, from his father, from Ibn Abi Umayr, from Hammad, from al-Halabi, from Abu Abdillah عليه السلام, peace be upon him: Imam al-Sadiq عليه السلام said: “If you reach the imam (of prayer) and he has already bowed, and you say the takbir and bow before the imam (of prayer) raises his head, then you have caught the rak’ah. But if the imam (of prayer) raises his head before you bow, then you have missed the rak’ah.”