Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings of Allah be upon him) said: Whoever forgets to pray a prayer or sleeps through it, its expiation is only that he should pray it when he remembers it.
Hadith Referenceالمنتقى ابن الجارود / كتاب الصلاة / 239
Hadith Gradingغلام مصطفےٰ ظهير امن پوري:صحيح
Hadith Takhrijاز غلام مصطفےٰ ظهير امن پوري:«صحيح البخاري : 597 ، صحيح مسلم : 684»