The narrators of traditions (Hadiths) have said that after reciting some verses of the Qur’an or at the end of some chapters of holy Book, Imam Reza (A.S) was quietly or loudly repeating some phrases some of which Raja ibn Abi Al-Zahhak has narrated for us.

He narrates: “Imam Reza (A.S) was always reciting ‘In the Name of God, the Compassionate, the Merciful”‌ loudly in all his daily prayers; quickly after that he was reciting the verse “Say (O Muhammad): "He is Allah, (the) One”‌, he was whispering ‘He is the One’; when he finished Al-Ikhlaas Chapter, he said thrice: “Such is indeed our Lord .”‌

When he was reciting Al-Kafiroon, he was whispering the Surah: “Say (O Muhammad… ”‌, when it was finished, he said: “my Lord is Allah and my religion is Islam.”‌

Whenever he was reciting Surah At-Tin, he said at the end of the Surah: “Yes, God is the best”‌; also, whenever he was reciting Surah Al-Qiyamah, he then said: “Indeed my Lord Thou art Praiseworthy.”‌ Whenever he was reciting Surah Al-Jumu’ah, he was saying: “Say, ‘What is with Allah is better than diversion and than a transaction, and Allah is the best of providers.’”‌

Whenever he finished reciting Al-Fatihah, he then said: “[All] praise is [due] to Allah, Lord of the worlds”‌ and if he was reciting Al-A’la, he then said: “Exalt the name of your Lord, the Most High,”‌

Source: Tebyan