Sunan an-Nasa'i 1300

Qutaybah narrated to us: Khalaf ibn Khalifah narrated to us, from Hafs, the nephew of Anas, from Anas ibn Malik, who said: I was sitting with the Messenger of Allah (ﷺ)—that is, sitting—while a man stood praying. When he bowed, prostrated, and recited the tashahhud, he supplicated, saying: “O Allah, I ask You, for all praise belongs to You. There is no deity but You, the Bestower, Originator of the heavens and the earth, Possessor of majesty and honor, O Ever-Living, O Sustainer. I ask You.” The Prophet (ﷺ) said to his companions, “Do you know what he supplicated with?” They said, “Allah and His Messenger know best.” He said: “By the One in whose hand is my soul, he called upon Allah by His great name: when He is called upon by it, He responds, and when He is asked by it, He gives.”