Samura bin Jundab reported that he memorized from the Messenger of Allah ﷺ two pauses, a pause when he pronounced the opening takbir, and a pause when he finished reciting "not of those who have earned Your anger, nor of those who have gone astray" [Fatihah 1:7]. Samura retained this, but Imran bin Husayn disputed it with him. So they wrote about it to Ubayy bin Kaab, and his letter to them, or his reply to them, stated that Samura had remembered correctly.
فحدث سمرة بن جندب أنه حفظ عن رسول الله ﷺ سكتتين، سكتة إذا كبر، وسكتة إذا فرع من قراءة{غير المغضوب عليهم ولا الضالين} فحفظ ذلك سمرة، وأنكر عليه عمران بن حصين، فكتبا في ذلك إلى أبي بن كعب، وكان في كتابه إليهما- أو في رده إليهما: أن سمرة قد حفظ.
Reported by Abu Dawud (779), and this is his wording, Tirmidhi (251), and Ibn Majah (844, 845), all of them through various chains from Saeed, from Qatada, from Hasan, from Samura. Tirmidhi said, "Hasan." Ibn Khuzayma (1578), Ibn Hibban (1807), and Hakim (1/215) graded it sahih, and Hakim said, "Sahih according to the criteria of the two Shaykhs (Bukhari and Muslim), though they did not include it with this wording. They only agreed on the hadith of Umara bin Qaqa, from Abu Zura, from Abu Hurairah, who said, when the Prophet ﷺ said the takbir, he would pause silently between the takbir and the recitation. As for the hadith of Samura, no one should imagine that Hasan did not hear from Samura, for he did in fact hear from him."I say, it has already been mentioned that scholars, including Bukhari, Ali bin Madini, and others, held that Hasan heard from Samura without restriction. Yahya bin Saeed Qattan and a group of others said, it is a written document that Samura wrote for his sons, and Hasan used to narrate from it, and this is wijada. Wijada is one of the recognized methods of transmitting a connected hadith. So if the hadith is established as sound up to Hasan, then it is sahih. This is what the compilers of the sahih collections, other than the two Shaykhs, along with the compilers of the Sunan works and the Musnad works, relied upon, and they included this hadith in their books.It has also been narrated, regarding the follower reciting Surah Fatihah during the imam's pause, from Abu Salama bin Abdul-Rahman, Urwa bin Zubayr, Saeed bin Jubayr, Ata bin Abu Rabah, and Makhul Shami. Tirmidhi said, "This is the view of more than one scholar, who recommend that the imam remain silent after opening the prayer and after finishing the recitation. This is also the view of Ahmad, Ishaq, and our companions."As for those who held this hadith to be daif, they said that Hasan did not hear from Samura except the hadith about aqiqah, and that Hasan, despite his great standing, was known to practice tadlis, and furthermore the narrators differed regarding him. Yunus and Ashath reported from him that the second pause, occurring after finishing the entire recitation, comes before the ruku. But Qatada reported from him that it comes after reciting "not of those who have incurred Your wrath, nor of those who have gone astray" [Fatihah 1:7].Abu Dawud pointed to some of this disagreement in his Sunan. Some scholars gathered these pauses together and said there are three. The second is after Surah Fatihah, so that the follower may recite Surah Fatihah. The third is after reciting the additional surah, before the ruku, and this one is brief, meant only to let one catch one's breath. This is why Uzai, Shafii, and Abu Thawr said, "It is due upon the imam to pause once after the first takbir, and to pause once after finishing the recitation of Surah Fatihah, and after finishing the recitation, so that those behind him may recite Surah Fatihah."See Istidhkar (4/238).