Further reports on this subject

Sayyiduna Abdullah bin Abi Awfa (may Allah be pleased with him) narrates: A man came while we were in the row, praying behind the Prophet (peace and blessings be upon him). The man joined the row and said: "Allah is the Greatest, truly great; and I declare Allah Almighty free of every imperfection, morning and evening." The narrator says: The Muslims raised their heads and showed their disapproval of the man. The Muslims said: "Who is this man raising his voice above the voice of the Messenger of Allah?" When the Prophet (peace and blessings be upon him) had completed the prayer, he said: "Who is this man with the loud voice?" It was said: "O Messenger of Allah! It is this one." The Prophet (peace and blessings be upon him) said: "By Allah, I saw your words ascending towards the heaven until a door was opened for them, and they entered through it."
Ahmad and al-Tabarani in al-Mu'jam al-Kabir recorded it, and its narrators are "thiqat" (trustworthy).

Sayyiduna Samurah bin Jundub (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) used to say to us: When any of you prays, let him recite: "O Allah! Put as much distance between me and my sins as You have put between the East and the West. O Allah! I seek refuge in You from withholding Your generosity from me on the Day of Resurrection. O Allah! Cleanse me of my sins as a white garment is cleansed of dirt. O Allah! Keep me alive as a Muslim and cause me to die as a Muslim."
Al-Bazzar and al-Tabarani in al-Mu'jam al-Kabir recorded it, and its chain is "da'if" (weak).

Sayyiduna Samurah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) used to say: "O Allah! Put as much distance between me and my sins as You have put between the East and the West, and cleanse me of my faults as You have cleansed a white garment of dirt."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its chain is hasan (good).

Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) says: The Prophet (peace and blessings be upon him) used to teach us that when we begin the prayer we should recite at its start: "You are free of every imperfection, O Allah, and praise belongs to You; Your name is blessed, Your majesty is exalted, and there is no god besides You." The narrator says: Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) used to teach us this and say: The Prophet (peace and blessings be upon him) used to recite these words.
Al-Tabarani recorded it in al-Mu'jam al-Awsat. The narrator Abu Ubaydah did not hear from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him). The author recorded it in al-Mu'jam al-Kabir in abridged form; its chain contains a narrator Mas'ud bin Sulayman, about whom Abu Hatim says: He is majhul (unknown).

Ibn Jurayj narrates: Someone whom I consider truthful told me about Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him), Sayyiduna Umar (may Allah be pleased with him), Sayyiduna Uthman (may Allah be pleased with him) and Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that at the beginning of the prayer, before the recitation, these men used to recite: "You are free of every imperfection, O Allah, and praise belongs to You; Your name is blessed, Your majesty is exalted, and there is no god besides You."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its chain contains a narrator who is not named.

Sayyiduna Wathilah (may Allah be pleased with him) narrates: At the beginning of the prayer the Prophet (peace and blessings be upon him) used to recite: "You are free of every imperfection, O Allah; praise belongs to You; Your name is blessed, Your majesty is exalted, and there is no god besides You."
Al-Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat. Its chain contains a narrator Amr bin al-Husayn, and he is "da'if" (weak).

Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates: When the Prophet (peace and blessings be upon him) began the prayer, he would recite: "I have turned my face towards the One who created the heavens and the earth; (I have turned my face to Him) remaining upon the upright religion, as a Muslim, and I am not of the polytheists. You are free of every imperfection, O Allah, and praise belongs to You; Your name is blessed, Your majesty is exalted, and there is no god besides You. Indeed my prayer, my sacrifice, my life and my death belong to Allah Almighty, the Lord of all the worlds, who has no partner. This is what I have been commanded, and I am one of the Muslims."
Al-Tabarani recorded it in al-Mu'jam al-Kabir. Its chain contains a narrator Abdullah bin Amir al-Aslami, and he is "da'if" (weak).

Sayyiduna Abu Rafi' (may Allah be pleased with him) narrates: I came across a document which mentioned what the Prophet (peace and blessings be upon him) used to recite at the beginning of the prayer when he said the takbir. He used to recite: "Indeed I have turned my face, remaining upon the upright path, towards the One who created the heavens and the earth, and I am not of the polytheists. Indeed my prayer, my sacrifice, my life and my death belong to Allah Almighty, the Lord of all the worlds; He has no partner. This is what I have been commanded, and I am one of the Muslims. O Allah! You are the King; there is no god besides You. You are free of every imperfection, and praise belongs to You. You are my Lord and I am Your servant; You have no partner. I have wronged myself and I confess my sin, so forgive all my sins, for none forgives sins except You. Here I am at Your service, and good fortune is attained from You; all good is in Your hands. There is no place of safety and no refuge from You except in You. I seek Your forgiveness and I turn to You in repentance." (The narrator says:) After this the Prophet (peace and blessings be upon him) would recite (the Qur'an).
Al-Tabarani recorded it in al-Mu'jam al-Kabir. Its chain contains a narrator Muhammad bin Ishaq; he is "thiqah" (trustworthy) but a mudallis (one who conceals defects in the chain), and he narrated this with 'an'anah (using "from"). The remaining narrators of this report have been declared trustworthy.

Sayyiduna Anas (may Allah be pleased with him) narrates: When the Prophet (peace and blessings be upon him) said the takbir, he would raise both his hands until he brought them level with his ears, and then he would recite: "You are free of every imperfection, O Allah, and praise belongs to You; Your name is blessed, Your majesty is exalted, and there is no god besides You."
Al-Tabarani recorded it in al-Mu'jam al-Awsat, and its narrators have been declared trustworthy.

Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates: When the Prophet (peace and blessings be upon him) began the prayer, he would first recite Surah al-Fatihah and then remain silent for a short while.
Al-Tabarani recorded it in al-Mu'jam al-Awsat, and its narrators have been declared trustworthy.

Sayyiduna Hudhayfah bin al-Yaman (may Allah be pleased with him) narrates: One night I came to the Prophet (peace and blessings be upon him). He performed ablution and stood up to pray. I came to him and stood on his left side, so he moved me to stand on his right side. Then he recited: "Glory be to Allah Almighty, the Possessor of dominion, might, grandeur and majesty."
Al-Tabarani recorded it in al-Mu'jam al-Awsat, and its narrators have been declared trustworthy.

Sayyiduna Abu Tha'labah al-Khushani (may Allah be pleased with him) narrates: Once the Prophet (peace and blessings be upon him) was praying, and during it he heard a man reciting this supplication: "All praise belongs to Allah Almighty, abundant, pure and blessed praise, such as befits the majesty of our Lord." When the Prophet (peace and blessings be upon him) completed the prayer, he asked: "Who was the one who recited these words? I saw twelve angels rushing towards these words." Then the Prophet (peace and blessings be upon him) kept his gaze on those angels until they disappeared behind the veil. The Prophet (peace and blessings be upon him) said: "On the Day of Resurrection these words will come to you with their seal, and you will receive the like of it."
Al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains a narrator Muhammad bin Yazid bin Sinan (al-Rahawi), whom Yahya bin Ma'in, al-Bukhari (may Allah have mercy on him) and al-Nasa'i (may Allah have mercy on him) declared da'if (weak), while Ibn Hibban declared him "thiqah" (trustworthy).