Samura said, "I memorized two pauses in the prayer. One pause when the imam says the opening takbir, before he begins to recite, and another pause when he finishes reciting al-Fatihah and a surah, just before bowing."Imran bin Husayn objected to this and disputed it with him. So they wrote about the matter to Madinah, to Ubayy, and Ubayy confirmed what Samura had said.
حدثنا يعقوب بن إبراهيم حدثنا إسمعيل عن يونس
قال سمرة حفظت سكتتين في الصلاة سكتة إذا كبر الإمام حتى يقرأ وسكتة إذا فرغ من فاتحة الكتاب وسورة عند الركوع قال فأنكر ذلك عليه عمران بن حصين قال فكتبوا في ذلك إلى المدينة إلى أبي فصدق سمرة
[Sahih] Ibn Majah related it in "Establishing the Prayers," chapter on the imam's two pauses, no. 845, from the hadith of Ismail bin Ulaya, through this route. See also the two following hadiths.Hasan's narration from Samura is from a written record, and narrating from a written record is valid.