The One Who sleeps through Prayer
Question :
When should 'Isha' prayer be made up by one who slept through it and did not remember until after he had prayed Fajr prayer? And should he pray it with its like, or should he pray it when he remembers it?
Answer:
It has been reported in an authentic Hadith that the Prophet said:
"Whoever slept through a prayer or forgot it, should pray it when he remembers it, and there is no expiation required for it except this.»
Then he recited the Words of Allah, the Most High:
...and offer prayers perfectly (Igamatus-Salat) for My remembrance.
And there is no difference between 'Isha' prayer and any other prayer, so if he wakes and the time has already passed for the performance of the prayer, then he must pray it immediately and he must not delay it until a similar time (the next day); he must pray it the moment he becomes aware of it, even if it be a time when it is (normally) forbidden to pray or the time for another prayer. But if he fears that the time for the present prayer will expire, then he may pray it first and then make up for the missed prayer after it. And Allah knows best.
Source:
Ibn Jibreen
Fatawa Islamiyah, Vol. 2 Pages 200-201