Ali bin Abi Talib narrated that

when the Messenger of Allah (ﷺ) would stand for the obligatory prayer, he would raise his hands to the level of his shoulder, and he would do this [also] when he finished his recitation and intended to bow, and he would do it when he raised his head from Ruku`, and he would not raise his hands in any of his prayers while he was seated. When he would rise from the two prostrations, he would likewise raise his hands, and say the Takbir, and when he opened his Salat after the Takbir, he would say: “I have directed my face towards the One who has created the heavens and the earth, as a Hanif, and I am not of the idolaters. Indeed, my Salat, my sacrifice, my living, my dying, is for Allah, the Lord of all that exists, without partner, and with this have I been ordered and I am of the Muslims. O Allah, You are the King, there is none worthy of worship except You. Glorified are You, You are My Lord, and I am Your slave, I have wronged myself and I admit to my sin, so forgive me all my sins, verily, there is none who forgives sins but You, and guide me to the best of manners, none guides to the best of them except You, and turn away from me the evil of them, none turns away from me the evil of them except You, I am here in Your obedience and aiding Your cause, and I am reliant upon You and ever-turning towards You, [and] there is no refuge from You nor hiding place from You except (going) to You, I seek Your forgiveness, and I repent to you (Wajjahtu wajhiya lilladhī faṭaras-samāwāti wal-arḍa ḥanīfan wa mā ana min al-mushrikīn, inna ṣalātī wa nusukī wa maḥyāya wa mamātī lillāhi rabbil-`ālamīn, lā sharīka lahū wa bidhālika umirtu wa ana min al-muslimīn. Allāhumma antal-maliku lā ilāha illā ant, subḥānaka anta rabbī, wa ana `abduka ẓalamtu nafsī wa`taraftu bidhanbī faghfirlī dhunūbī jamī`an, innahū lā yaghfir adh-dhunūba illā ant. Wahdinī li-aḥsanil-akhlāqi lā yahdī li-aḥsanihā illā ant. Waṣrif `annī sayyi’ahā lā yaṣrifu `annī sayyi’aha illā ant. Labaika wa sa`daika, wa ana bika wa ilaika, [wa] lā manjā minka wa lā malja’a illā ilaik, astaghfiruka wa atūbu ilaik).” Then he would recite, then when he would bow, his speech in his Ruku`, would be to say: “O Allah, to You have I bowed, and in You have I believed, and to You have I submitted (in Islam), and You are my Lord. My hearing, my sight, my brain and my bones are humbled to Allah, the Lord of the Worlds all that exists (Allāhumma laka raka`tu wa bika āmantu wa laka aslamtu wa anta rabb ī. Khasha`a sam`ī wa baṣarī wa mukhkhī wa `aẓmī lillāhi, rabbil-`ālamīn).” Then, when he raised his head from Ruku he would say: “Allah hears the one who praises him (Sami`a Allāhu liman ḥamidah).” Then he would follow it with: “O Allah, our Lord, to You is praise filling the heavens and the earth and filling whatever You wish of things afterward (Allāhumma rabbanā wa lakal-ḥamdu mil’as-samāwāti wal-arḍi, wa mil’a mā shi’ta min shay’in ba`d.).” Then, when prostrated he would say in his prostration: “O Allah, to You have I prostrated, and in You have I believed, and to You have I submitted (in Islam), and You are my Lord, my face has prostrated to the One that created it, and granted its hearing and sight, Blessed is Allah, the Best of Creators (Allāhumma laka sajadtu wa bika āmantu wa laka aslamtu wa anta rabbī, sajada wajhi lilladhī khalaqahū wa shaqqa sam`ahū wa baṣarahū, tabārak Allāhu ahsanul-khāliqīn).” When he was finished with his Salat, we would say: “O Allah, forgive me what I have done, before and after, and what I have hidden, and what I have done openly, and You are my Deity, there is none worthy of worship except You (Allāhummaghfirlī mā qaddamtu wa mā akhkhartu wa mā asrartu wa mā a`lantu, wa anta ilāhī lā ilāha illā ant).”