Sunan an-Nasa'i 188

سنن النسائي#188Sahih

أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الأَغَرِّ، - وَهُوَ ابْنُ الصَّبَّاحِ - عَنْ خَلِيفَةَ بْنِ حُصَيْنٍ، عَنْ قَيْسِ بْنِ عَاصِمٍ، أَنَّهُ أَسْلَمَ فَأَمَرَهُ النَّبِيُّ صلى الله عليه وسلم أَنْ يَغْتَسِلَ 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

Scholarly Authentication

The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:

Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih

In-book reference: 1:189