سنن ابودوٗد · Hadith 821

Abu Hurairah reported the Messenger of Allah ﷺ as saying: If anyone observes a prayer in which he does not recite Umm al-Quran, it is incomplete, it is incomplete, it is incomplete, and deficient. (The narrator said) I said: Abu Hurairah, sometime I pray behind the imam (then what should I do)? Pressing my hand he replied: O Persian, recite it inwardly, for I heard the Messenger of Allah ﷺ as saying that Allah, Most High, has said: I have Me and the Half for my servant and My servant will receive what he asks. The Messenger of Allah ﷺ said: Recite. When the servant says: “praise be to Allah, the Lord of the Universe, ” Allah, Most High says: “My servant has praised me. ” When the servant says: “ The Compassionate, the merciful, “Allah Most High says: “My servant has lauded me. ” When the servant says: “Owner of the Day of Judgment, ” Allah, Most High, says: “My servant has glorified Me” When the servant says: “ Thee do we worship and of thee we ask help. “ (Allah says) “This is between Me and My servant, and My servant will receive what he asks. ” When the servant says: “ Guide us to the Straight Path, the path of those whom thou hast favoured, not ( the path) of those who earn thine anger nor of those who go astray, ” (Allah says: ) “This is for My servant, and My servant will receive what he asks. ”