سنن النسائي

It was narrated that Anas bin Malik said: "I was sitting with the Messenger of Allah (ﷺ) and a man was standing and praying. When he bowed, prostrated and recited the tashahhud, he supplicated, and in his supplication he said: "Allahumma inni as'aluka bi-anna lakal-hamd, lailaha illa ant, al-mannanu badi'us-samawati wal-ard, ya dhal-jalali wal-ikram! Ya hayyu ya qayyum! Inni as'aluka. (O Allah, indeed I ask You since all praise is due to You, there is none worthy of worship but You, the Bestower, the Creator of the heavens and earth, O Possessor of majesty and honor, O Ever-living, O-Eternal, I ask of You.)' The Prophet (ﷺ) said: 'Do you know what he has supplicated with?' They said: "Allah (SWT) and His Messenger know best." He said: 'By the One in Whose Hand is my soul, he called upon Allah by His greatest Name, which, if He is called by it, He responds, and if He is asked by it, He gives.'"