The Messenger of Allah ﷺ said, "When the prayer is announced, do not stand up until you see me."
قال رسول الله ﷺ: إذا أقيمت الصلاة فلا تقوموا حتى ترؤني.
Bukhari narrated it in adhan (637) and Muslim in masjids (604), both through Yahya bin Abu Kathir, from Abdullah bin Abu Qatada (Muslim paired him with Abu Salama), from Abu Qatada, and he related the hadith.In Bukhari, from Muslim bin Ibrahim, he said, Hisham told us, he said, Yahya wrote to me from Abdullah bin Abu Qatada, and he related the hadith. Writing is one of the recognized methods of transmission. He also narrated it (638) from Abu Naeem, who said, Shayban told us, and he related the same, adding at the end, "And be calm," except that Muslim did not mention this addition in the narration of Shayban after mentioning the corroborating narrations.The author, may Allah have mercy on him (meaning Bukhari), said, Ali bin Mubarak corroborated him. The author connected this corroboration in full in the book of Friday (909), where he said, Amr bin Ali told us, he said, Abu Qutayba told me, he said, Ali bin Mubarak told us, from Yahya bin Abu Kathir, from Abdullah bin Abu Qatada, I do not know it except from his father, from the Prophet ﷺ, who said, "Do not stand until you see me, and be calm."Muawiya bin Salam also corroborated them both, as Abu Dawud mentioned (539), saying, Muawiya bin Salam and Ali bin Mubarak narrated it from Yahya, and both of them said in it, "until you see me, and be calm." Ismaili connected this suspended narration through Walid bin Muslim, from Muawiya bin Salam and Shayban, both from Yahya. See Fath al-Bari (2/121).The meaning of his statement, "and be calm," is that you should not push one another when standing for the prayer, so that whoever is far from the first row should not try to hurry without regard for pushing and crowding, for that goes against dignified composure. Ibn Rushayd explained another meaning, saying, "The subtle point in prohibiting that is so that their standing does not become a cause for him hurrying to enter into the prayer, which would contradict his intended manner of dignified composure." See Fath [Bari].The hadith of Jabir bin Samura, the hadith of Abu Hurairah, and the hadith of Abu Qatada are contradicted by the hadith of Bilal, that he used to give the adhan when the sun had declined, and would not give the call to begin the prayer until the Prophet ﷺ came out. When he came out, he would give the call to begin the prayer as soon as he saw him. It is possible to reconcile these hadiths by saying that Bilal used to watch for the Prophet's ﷺ coming out from a place where no one else could see him, or only a few could, so as soon as he came out, he would give the call to begin the prayer, and the people would not stand until they saw him, and then he would not take his place until they had straightened the rows.His statement in the hadith of Abu Hurairah, "so the people would take their places before the Prophet ﷺ took his," was narrated by Abu Dawud (541) with a sahih chain, and in it Walid bin Muslim explicitly stated that he was told directly, so this is to be understood as applying when the Prophet ﷺ was in the masjid, or that he did that once or twice to demonstrate that it was permissible. Otherwise the basic principle is that the call to begin the prayer should not be given until the imam comes out, so that standing does not become too long for them, since something might come up that delays him, as Qadi Iyad and others have said.Nawawi, may Allah have mercy on him, said, "The scholars, from the early generations and those who came after them, differed about when the people should stand for the prayer, and when the imam should say the opening takbir. The view of Shafii, may Allah have mercy on him, and a group of scholars, is that it is recommended that no one stand until the caller has finished the call to begin the prayer. Qadi Iyad related from Malik, may Allah have mercy on him, and the majority of scholars, that it is recommended that they stand when the caller begins the call to begin the prayer. Anas used to stand when the caller said, 'The prayer has begun,' and Ahmad, may Allah have mercy on him, held this same view. Abu Hanifa and the Kufans said that they stand in the row when he says, 'Come to the prayer,' and when he says, 'The prayer has begun,' the imam says the opening takbir. The majority of scholars, from the early and later generations, said that the imam does not say the opening takbir until the caller has finished the call to begin the prayer."I say, the statement of the jurists is to be understood as meaning that the imam, before the call to begin the prayer, straightens the rows and closes the gaps, then orders the caller to give the call to begin the prayer, and then says the opening takbir. Ibrahim Nakhai said, "So when he says, 'The prayer has begun,' the imam says the opening takbir." Muhammad bin Hasan mentioned this in the book Athar and said, "This is what we adopt, and it is the view of Abu Hanifa." Otherwise it would contradict the sahih and explicit sunnah.