Hadith 3:55
Anas said that when the Prophet entered the privy he took off his ring. Abu Dawud, Nasa’i and Tirmidhi transmitted it. Tirmidhi said this is a hasan sahih gharib tradition, and Abu Dawud said this is a rejected ( munkar ) tradition. His version has "laid down” instead of "took off".
عَنْ أَنَسٍ قَالَ: كَانَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا دَخَلَ الْخَلَاءَ نَزَعَ خَاتَمَهُ. رَوَاهُ أَبُو دَاوُدَ وَالنَّسَائِيُّ وَالتِّرْمِذِيُّ وَقَالَ: هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ غَرِيبٌ وَقَالَ أَبُو دَاوُدَ: هَذَا حَدِيثٌ مُنْكَرٌ. وَفِي رِوَايَتِهِ وَضَعَ بَدَلَ نزع
Original Reference: Mishkat al-Masabih 343