Sunan an-Nasa'i #222 · The Book of Purification

Sunan an-Nasa'iIt was narrated from Ghudaif bin Al-Harith that he asked 'Aishah in which part of the night would the Messenger of Allah
Sunan an-Nasa'i · Book 1 · The Book of Purification
Sunan an-Nasa'i · كتاب 1 · كتاب الطهارة
"Sometimes he performed Ghusl at the beginning of the night and sometimes he performed Ghusl at the end." I said: "Praise be to Allah Who has made the matter flexible
أَخْبَرَنَا عَمْرُو بْنُ هِشَامٍ، قَالَ حَدَّثَنَا مَخْلَدٌ، عَنْ سُفْيَانَ، عَنْ أَبِي الْعَلاَءِ، عَنْ عُبَادَةَ بْنِ نُسَىٍّ، عَنْ غُضَيْفِ بْنِ الْحَارِثِ، أَنَّهُ سَأَلَ عَائِشَةَ - رضى الله
عنها - أَىُّ اللَّيْلِ كَانَ يَغْتَسِلُ رَسُولُ اللَّهِ صلى الله عليه وسلم قَالَتْ رُبَّمَا اغْتَسَلَ أَوَّلَ اللَّيْلِ وَرُبَّمَا اغْتَسَلَ آخِرَهُ ‏.‏ قُلْتُ الْحَمْدُ لِلَّهِ الَّذِي جَعَلَ فِي الأَمْرِ سَعَةً ‏.‏
Reference : Sunan an-Nasa'i 222In-book reference : Book 1, Hadith 223