Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bukhari:1146Abū al-Walīd > Shuʿbah > Sulaymān > Shuʿbah > Abū Isḥāq > al-Aswad > Saʾalt

I asked ʿAisha "How is the night prayer of the Prophet?" She replied, "He used to sleep early at night, and get up in its last part to pray, and then return to his bed. When the Mu'adh-dhin pronounced the Adhan, he would get up. If he was in need of a bath he would take it; otherwise he would perform ablution and then go out (for the prayer)."  

البخاري:١١٤٦حَدَّثَنَا أَبُو الْوَلِيدِ حَدَّثَنَا شُعْبَةُ وَحَدَّثَنِي سُلَيْمَانُ قَالَ حَدَّثَنَا شُعْبَةُ عَنْ أَبِي إِسْحَاقَ عَنِ الأَسْوَدِ قَالَ

سَأَلْتُ عَائِشَةَ ؓ كَيْفَ صَلاَةُ النَّبِيِّ ﷺ بِاللَّيْلِ قَالَتْ كَانَ يَنَامُ أَوَّلَهُ وَيَقُومُ آخِرَهُ فَيُصَلِّي ثُمَّ يَرْجِعُ إِلَى فِرَاشِهِ فَإِذَا أَذَّنَ الْمُؤَذِّنُ وَثَبَ فَإِنْ كَانَ بِهِ حَاجَةٌ اغْتَسَلَ وَإِلاَّ تَوَضَّأَ وَخَرَجَ