Yahya related to me from Malik from Zayd ibn Aslam from Ata ibn
Yasar that the Messenger of Allah, may Allah bless him and grant him
peace, sent a gift to Umar ibn al-Khattab, and Umar returned it. The
Messenger of Allah, may Allah bless him and grant him peace, said,
"Why did you return it?" He said, "Messenger of Allah, didn't you tell
us that it is better for us not to take anything from anyone?" The
Messenger of Allah, may Allah bless him and grant him peace, said,
"That is by asking. Provision which Allah gives you is different from
asking." Umar ibn al-Khattab said, "By the One in whose hand my self
is, I will not ask anything from anyone, and anything that comes to me
without my asking for it, I will accept."
Muwatta Malik Book 58, Hadith 9
Mihjan bin Al-Adra' narrated to him that the Messenger of Allah (ﷺ) entered the masjid and there was a man who had finished his prayer and he was reciting the tashahhud. He said: "Allahumma inni as'aluka ya Allah! Bi-annakal-Wahidul-Ahad us-Samad, alladhi lam yalid wa lam yowled, wa lam yakun lahu kufuwan ahad, an taghfirali dhunubi, innaka antal-Ghafurur-Rahim (O Allah, I ask of You, O Allah, as You are the One, the Only, the Self-Sufficient Master, Who begets not nor was He begotten, and there is None equal or comparable to Him, forgive me my sins, for You are the Oft-Forgiving, Most Merciful.)" The Messenger of Allah (ﷺ) said: "He has been forgiven," three times.
Sunan an-Nasa'i Book 13, Hadith 123