The Book of Faith
وَحَدَّثَنَا هُرَيْمُ بْنُ عَبْدِ الأَعْلَى الأَسَدِيُّ، حَدَّثَنَا الْمُعْتَمِرُ بْنُ سُلَيْمَانَ، قَالَ سَمِعْتُ أَبِي يَذْكُرُ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، قَالَ لَمَّا نَزَلَتْ هَذِهِ الآيَةُ . وَاقْتَصَّ الْحَدِيثَ . وَلَمْ يَذْكُرْ سَعْدَ بْنَ مُعَاذٍ وَزَادَ فَكُنَّا نَرَاهُ يَمْشِي بَيْنَ أَظْهُرِنَا رَجُلٌ مِنْ أَهْلِ الْجَنَّةِ .This hadith is narrated on the authority of Anas by another chain of transmitters in which there is no mention of Sa'd b. Mu'adh, but the following words are there:We observed a man, one of the dwellers of Paradise, walking about amongst us
From Sahih Muslim, whose reports the scholars accept as authentic.