I prayed behind the Messenger of Allah ﷺ. When he began the prayer, he said the takbir and raised his hands until they were level with his ears. Then he recited the Opening of the Book, and when he finished it, he said "Ameen," raising his voice with it.
أخبرنا قتيبة قال حدثنا أبو الأحوص عن أبي إسحق
صليت خلف رسول الله ﷺ فلما افتتح الصلاة كبر ورفع يديه حتى حاذتا أذنيه ثم يقرأ بفاتحة الكتاب فلما فرغ منها قال آمين يرفع بها صوته
No references are available.
[Sahih] Ahmad narrated it: 4/318, from the hadith of Abu Ishaq, through him, and it is in Kubra, Abi, h: 953. Abdul-Jabbar did not hear from his father, see h: 883, 1405. The hadith has many corroborating narrations in Dawud and Tirmidhi and others.