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.
Sunan Abi Dawud Book 5, Hadith 48
Ibn `Umar intended to perform Hajj in the year of the Hajj of Al-Harawriya during the rule of Ibn Az-
Zubair. Some people said to him, "It is very likely that there will be a fight among the people, and we
are afraid that they might prevent you (from performing Hajj)." He replied, "Verily, in Allah's Messenger (ﷺ)
there is a good example for you (to follow). In this case I would do the same as he had done. I make
you witness that I have intended to perform `Umra." When he reached Al-Baida', he said, "The
conditions for both Hajj and `Umra are the same. I make you witness that I have intended to perform
Hajj along with `Umra." After that he took a garlanded Hadi (to Mecca) which he bought (on the
way). When he reached (Mecca), he performed Tawaf of the Ka`ba and of Safa (and Marwa) and did
not do more than that. He did not make legal for himself the things which were illegal for a Muhrim
till it was the Day of Nahr (sacrifice), when he had his head shaved and slaughtered (the sacrifice) and
considered sufficient his first Tawaf (between Safa and Marwa), as a (Sa`i) for his Hajj and `Umra
both. He then said, "The Prophet (ﷺ) used to do like that."
Sahih al-Bukhari Book 25, Hadith 186