Chapter 49: The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness
Qatada asked Anas which Supplication Allah' s Apostle (ﷺ) frequently made. He said: The supplication that he (the Prophet made very frequently is this: " O Allah, grant us the good in this world and the good in the Hereafter and save us from the torment of Hell-Fire." He (Qatada) said that whenever Anas had to supplicate he made this very supplication, and whenever he (intended) to make another supplication he (inserted) this very supplication in that.
Sahih Muslim 2690a