Bara bin Azib demonstrated for us by placing his hands down, supporting himself on his knees, and raising his backside, then he said, "This is how the Messenger of Allah ﷺ used to prostrate."
وصف لنا البراء بن عازب فوضع يديه، واعتمد على ركبتيه، ورفع عجيزته، وقال: هكذا كان رسول الله ﷺ يسجد.
Abu Dawud (896) and Nasai (1104) both narrated it through the hadith of Sharik, from Abu Ishaq, as mentioned. Ibn Khuzayma also narrated it in his Sahih (646), as did Ahmad (18701) and Bayhaqi (2/115), all through this same route, and Ahmad and Bayhaqi added, "and he spread apart," while Bayhaqi added, "and he stretched out his hands." Sharik is Ibn Abdullah Nakhai, who has poor memory, but he is corroborated regarding part of the description of the sujud. Nasai (1105), Ibn Khuzayma (647), Hakim (1/227–228), and Bayhaqi all narrated it through the route of Yunus bin Abu Ishaq, from Abu Ishaq, from Bara, who said, "When the Messenger of Allah ﷺ prayed, he arched his back."Taking both routes together, the hadith reaches the level of hasan, and Nawawi likewise graded it hasan in Al-Majmu (3/435–436). His words, "he spread apart," with a doubled waw, mean that he kept his elbows and upper arms away from his sides. His words, "he arched his back," describe someone who does not stretch out fully in his bowing or in his sujud, as reported by Ibn Khuzayma from Nadr bin Shumayl.Khattabi said, as quoted in Awn al-Mabud, "He means that he raised his rear and leaned slightly forward, this being the explanation." And in Al-Nihayah it is said to mean that he opened his upper arms and kept them away from his sides, and raised his belly away from the ground.