Source: Fiqh-us-Sunnah, vol 2, # 33
‘Ikrimah reports from Ibn ‘Abbas that the Messenger of Allah said to ‘Abbas ibn ‘Abdal-Mutalib: “O ‘Abbas, O Uncle, shall I not give you, shall I not present to you, shall I not donate to you, shall I not tell you ten things which, if you do, Allah will forgive your first and last sins, past and present sins, intentional and unintentional sins, private and public sins? The ten actions are: pray four rak’at, reciting in every rak’ah al-Fatihah and a surah. And when you finish the Qur’anic recitation of the first rak’ah, say, while standing, ‘Subhanallah, al-hamdulillah, wa la ilaha illallah, wa Allahu Akbar‘ ['Glory be to Allah. All praise is due to Allah. There is no God except Allah. Allah is the greatest.'] fifteen times. Then make ruku’, and while you are in ruku’, say the same ten times; then stand, and say the same ten times. Then go down and make sajdah, and while you’re in sajdah, say the same ten times. Then sit after the sajdah, and say the same ten times. Then make sajdah, and say the same ten times. Then sit after the second sajdah, and say the same another ten times. That is seventy-five [repetitions of the phrases] in each rak’ah. Do that in each of the four rak’at. If you can pray it once a day, do so. If you cannot, then once every Friday. If you cannot do that, then once a year. And if you cannot do that then once in your life.“
This hadith is related by Abu Dawud, Ibn Majah, Ibn Khuzaimah in his sahih, and at-Tabarani. About this hadith al-Mundhiri says: “This hadith has been related through many chains and from a number of companions. The best of them is this one from ‘Ikrimah. A group of scholars have graded it to be sahih, including al-Hafez Abu Bakr al-‘Ajari, (al-Mundhiri’s teachers), Abu Muhammad ‘Abdurrahim al-Misri, and Abu al-Hassan al-Maqdisi.” Ibn alMubarak says: “The tasbih prayer is a greatly desired act and it is desirable that one should punctually observe it and never neglect it.