He saw the Prophet ﷺ raise his hands when he began the prayer. He said the takbir, and Hammam described it as level with his ears, then he wrapped himself in his garment and placed his right hand over his left. When he wanted to bow, he took his hands out from the garment, raised them, said the takbir, and bowed. When he said, "Allah hears whoever praises Him," he raised his hands. When he prostrated, he prostrated between his palms.
أنه رأى النبي ﷺ رفع يديه حين دخل في الصلاة. كبر- وصف همام حيال أذنيه- ثم التحف بثوبه، ثم وضع يده اليمنى على اليسرى. فلما أراد أن يركع أخرج يديه من الثوب، ثم رفعهما، ثم كبر فركع، فلما قال: سمع الله لمن حمده رفع يديه، فلما سجد سجد بين كفيه.
Muslim narrated it in the Book of Prayer (401) from Zuhayr bin Harb, who said, Affan narrated to us, who said, Hammam narrated to us, who said, Muhammad bin Jahada narrated to us, who said, Abdul-Jabbar bin Waail narrated to me, from Alqama bin Waail and a freedman of theirs, that both of them narrated to him from his father Waail bin Hajar, and he mentioned the hadith. The narrator left the position of the hands unspecified.Ibn Khuzayma narrated in his Sahih (479) from Abu Musa, who said, Muammal narrated to us, who said, Sufyan narrated to us, from Asim bin Kulayb, from his father, from Waail bin Hajar, who said, "I prayed with the Messenger of Allah ﷺ and he placed his right hand on his left hand on his chest."Bayhaqi said in Marifah (2/340), "We narrated it through some chains of the hadith of Asim bin Kulayb, from his father, from Waail bin Hajar, from the Prophet ﷺ, then he placed them on his chest."I say, the hadith of Ibn Khuzayma was mentioned by Nawawi in Sharh Muslim (4/115), Sharh Muhazzab (3/313), and Khulasa (1096), and by Hafiz in Fath al-Bari (2/224), and in Bulugh Maram (p. 53), and in Talkhis (1/224), and by Ibn Mulaqqin in Tuhfat al-Muhtaj (1/336), and by Ibn Abdul-Hadi in Muharrar (1/185). All of these remained silent and did not comment on Muammal, so in their view he is either sahih through corroborating and supporting narrations, or hasan.The verifying scholar Abdul-Hayy Lucknawi said in his commentary on Muwatta Muhammad, "It is established with Ibn Khuzayma and others, from the hadith of Waail, that the placing was on the chest." Taliq Mumajjad (2/67).The eminent scholar Mubarakpuri says, "It appears from this statement of Hafiz that the hadith of Waail is, in his view, sahih or hasan, because he mentioned here, for the purpose of determining the place of placing the hands, three hadiths, the hadith of Waail, the hadith of Hulb, and the hadith of Ali. He graded the hadith of Ali as daif and said, its chain is daif, but he remained silent about the hadith of Waail and the hadith of Hulb. Had they also been daif in his view, he would have clarified their weakness." End of quote. See Ibkar Minan (p. 196).As for Muammal, he is Ibn Ismail Adawi, a freedman of the family of Khattab, and it is also said a freedman of Banu Bakr, Abu Abdul-Rahman Basri. He narrated from Shuba and the two Sufyans and others, and from him narrated Ahmad bin Hanbal, Ishaq bin Rahawayh, Ali bin Madini, and others.Ibn Abu Khaythama said, on the authority of Ibn Main, "trustworthy."Uthman Darimi said, "I asked Ibn Main, what is his status? He said, trustworthy."Abu Hatim said, "Truthful, strict in following the sunnah, makes many mistakes."Ibn Saad said, "Trustworthy, makes many errors."A note of caution, it occurs in Tahzib and its source Tahzib Kamal, and in Mizan of Dhahabi (4/228), that Bukhari said about Muammal bin Ismail, "his hadith is objectionable." But Bukhari gave a biographical entry for Muammal bin Ismail in Tarikh al-Kabir (8/49), and Tarikh Saghir (219), and did not say about him "his hadith is objectionable." Rather, he mentioned neither criticism nor endorsement of him. As for his book Duafa, he did not give him an entry there at all.I fear that this may stem from an oversight, for after Muammal bin Ismail he gave an entry for Muammal Ibn Saeed and said about him, "his hadith is objectionable." So take note. And Allah knows best.Someone like this, his hadith is considered acceptable if other trustworthy narrators corroborate him, and we have indeed found someone who corroborated his narration of the hadith about placing the hands on the chest. See on this, Fath Ghafur fi Wad Aydi ala Sudur.