ذِكْرُ الِاسْتِحْبَابِ لِلْكَافِرِ إِذَا أَسْلَمَ أَنْ يَكُونَ اغْتِسَالُهُ بِمَاءٍ وَسِدْرٍ
It was narrated from Qais bin 'Asim that he accepted Islam, and the Prophet commanded him to perform Ghusl with water and lotus leaves. (Using translation from Nasāʾī 188)
«أَنَّهُ أَسْلَمَ فَأَمَرَهُ النَّبِيُّ ﷺ أَنْ يَغْتَسِلَ بِمَاءٍ وَسِدْرٍ»