It is narrated from Abu Mijlaz (may Allah have mercy on him) that he said: "Al-nashi'ah (the rising by night) is whatever is after Isha until the morning."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4755
Hadith Gradingمحدثین:صحيح
Hadith Takhrij«صحيح۔ اخرجه ابن نصر في قيام الليل كما في الدر المنثور 8/317»