Hadithcore
Bulugh al-Maram, 87

Narrated Anas bin Malik (rad):

Allah’s Messenger (ﷺ) used to remove his ring when entering the lavatory. [Reported by Al-Arba’a and it is defective].

عَنْ أَنَسِ بْنِ مَالِكٍ ‏- رضى الله عنه ‏- قَالَ: { كَانَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-إِذَا دَخَلَ اَلْخَلَاءَ وَضَعَ خَاتَمَهُ } أَخْرَجَهُ اَلْأَرْبَعَةُ, وَهُوَ مَعْلُول ٌ [1]‏ .‏

References2 variants
In-Book Reference
Book 1, Hadith 105
English Reference
Book 1, Hadith 93