Bulugh al-Maram
Asma’ bint ’Umais (RAA) narrated that Fatimah (RAA) (the daughter of the prophet (ﷺ) made a will that ‘Ali (RAA) was to wash her when she dies.’ Related by Ad-Daraqutni.
وَعَنْ أَسْمَاءَ بِنْتِ عُمَيْسٍ رَضِيَ اَللَّهُ عَنْهَا: { أَنَّ فَاطِمَةَ عَلَيْهَا اَلسَّلَامُ أَوْصَتْ أَنْ يُغَسِّلَهَا عَلِيٌّ رَضِيَ اَللَّهُ تَعَالَى عَنْهُ } رَوَاهُ اَلدَّارَقُطْنِيُّ 1 .
Reference