Sunan Abi Dawud Book 5, Hadith 48
The Messenger of Allah (ﷺ) said to al-Abbas ibn AbdulMuttalib: Abbas, my uncle, shall I not give you, shall I not present to you, shall I not donate to you, shall I not produce for you ten things? If you act upon them, Allah will forgive you your sins, first and last, old and new, involuntary and voluntary, small and great, secret and open.
These are the ten things: you should pray four rak'ahs, reciting in each one Fatihat al-Kitab and a surah. When you finish the recitation of the first rak'ah you should say fifteen times while standing: "Glory be to Allah", "Praise be to Allah", "There is no god but Allah", "Allah is most great". Then you should bow and say it ten times while bowing. Then you should raise your head after bowing and say it ten times. Then you should kneel down in prostration and say it ten times while prostrating yourself. Then you should raise your head after prostration and say it ten times. Then you should prostrate yourself and say it ten times. Then you should raise your head after prostrating and say it ten times in every rak'ah. You should do that in four rak'ahs.
If you can observe it once daily, do so; if not, then once weekly; if not, then once a month; if not, then once a year; if not, then once in your lifetime.
The Prophet (ﷺ) said: Prayer is to be offered in two rak'ahs; and you should recite the tashahhud at the end of two rak'ahs, and express your distress and humility and raise your hands and say praying: O Allah, O Allah. He who does not do so does not offer a perfect prayer.
Abu Dawud was asked about offering prayer at night in two rak'ahs. He said: They may be two if you like and four if you like.
AbulJawza' said: A man who attended the company of the Prophet (ﷺ) narrated to me (it is thought that he was Abdullah ibn Amr): The Prophet (ﷺ) said to me: Come to me tomorrow; I shall give you something, I shall give you something, I shall reward you something, I shall donate something to you. I thought that he would give me some present.
He said (to me when I came to him): When the day declines, stand up and pray four rak'ahs. He then narrated something similar.
This version adds: Do not stand until you glorify Allah ten times, and praise Him ten times, and exalt Him ten times, and say, "There is no god but Allah" ten times. Then you should do that in four rak'ahs. If you are the greatest sinner on earth, you will be forgiven (by Allah) on account of this (prayer).
I asked: If I cannot pray this the appointed hour, (what should I do)? He replied: Pray that by night or by day (at any time).
Abu Dawud said: Habban b. Hilal is the maternal uncle of Hilal al-Ra'i.
Abu Dawud said: This tradition has been narrated by al-Mustamir b. al-Riyyan from Ibn al-Jawza' from 'Abd Allah b. 'Amr without referring to the Prophet (ﷺ), - narrated as a statement of 'Abd Allah b. 'Amr himself (mauquf). This has also been narrated by Rawh b. al-Musayyab, and Ja'far b. Sulaiman from 'Amr b. Malik al-Nakri from Abu al-Jauza' from Ibn 'Abbas as his own statement (and not the statement of the Prophet). But the version of Rawh has the words: "The tradition of the Prophet (ﷺ)."