When the Prophet ﷺ finished reciting the Mother of the Quran, he would raise his voice and say, "Ameen."
كان النبي ﷺ إذا فرغ من قراءة أم القرآن، رفع صوته وقال: آمين.
Daraqutni (1274), Ibn Hibban (1806), Hakim (1/223), and Bayhaqi (2/58) all narrated it through the route of Ishaq bin Ibrahim Zubaydi, who said, Amr bin Harith narrated to me, Abdullah bin Salim narrated to me, from Zubaydi, Zuhri informed me, from Abu Salama and Saeed bin Musayab, from Abu Hurairah, and he related it.Daraqutni said, "This isnad is hasan." Hakim said, "Sahih according to the standard of the two Shaykhs (Bukhari and Muslim)." I say, it contains Ishaq bin Ibrahim bin Ala Zubaydi, about whom there is disagreement. Abu Hatim said, "A shaykh with nothing objectionable about him, but they envy him." Ibn Hibban mentioned him in Thiqat (8/163) and included a narration from him in his Sahih, and Daraqutni graded his hadith hasan while Hakim graded it sahih.The hadith has another isnad, which is what Abu Dawud (934) and Ibn Majah (853) both narrated through the route of Safwan bin Isa, who said, Bishr bin Rafi narrated to us, from Abu Abdullah the cousin of Abu Hurairah, from Abu Hurairah, who said, People stopped saying the Ameen. But the Messenger of Allah ﷺ, when he said, "not of those who have earned Your anger, nor of those who have gone astray" [Fatihah 1:7], would say, "Ameen," loud enough for the people of the first row to hear him, so the masjid would resound with it.However, it contains Bishr bin Rafi Harithi, who is daif in hadith, and Abu Abdullah the cousin of Abu Hurairah is unknown.Daraqutni also narrated it (1273, 1272) through the route of Bahr Saqqa, from Zuhri, from Abu Salama, from Abu Hurairah, from the Prophet ﷺ, and also from Zuhri, from Salim, from Ibn Umar, that the Messenger of Allah ﷺ, when he said, "nor of those who have gone astray" [Fatihah 1:7], would say, "Ameen," raising his voice with it. Daraqutni said, Bahr Saqqa is daif.The hadith becomes hasan when these two isnads are taken together.