The Book of Prayer
Bulugh al-Maram #325
كتاب الصلاة
وَفِي رِوَايَةٍ لَهُ: أَنَّ ذَلِكَ فِي صَلَاةِ اَللَّيْلِ.
And in another narration of Muslim:
“he used to say that in the night prayer...”
وَفِي رِوَايَةٍ لَهُ : أَنَّ ذَلِكَ فِي صَلَاةِ اَللَّيْلِ.
"he used to say that in the night prayer..."
— Bulugh al-Maram, Hadith 325