Riyad as-Salihin, Book 1, Hadith 153 (In-Book) ⓘ

'Umar bin Al-Khattab (May Allah be pleased with him) reported: Messenger of Allah said, "Should anyone fall asleep at night and fail to recite his portion of the Qur'an, or a part of it, if he recites it between the Fajr prayer and the Zuhr prayer, it will be recorded for him as though he had recited it during the night".[Muslim].

وعن عمر بن الخطاب رضي الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم‏:‏ ‏ "‏ من نام عن حزبه من الليل، أو عن شيء منه فقرأه ما بين صلاة الفجر وصلاة الظهر، كتب له كأنما قرأه من الليل‏" ‏ ‏(‏‏(‏رواه مسلم‏)‏‏)‏‏.‏