When entering the Khala', the Messenger of Allah [SAW] would take off his ring.  

أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ إِذَا دَخَلَ الْخَلاَءَ نَزَعَ خَاتَمَهُ  

When the Prophet ﷺ entered the privy, he removed his ring. Abu Dawud said: This is a munkar tradition, i.e. it contradicts the well-known version reported by reliable narrators. On the authority of Anas the well-known version says: The Prophet ﷺ had a silver ring made for him. Then he cast it off. The misunderstanding is on the part of Hammam (who is the narrator of the previous tradition mentioned in the text). This is transmitted only by Hammam.  

كَانَ النَّبِيُّ ﷺ إِذَا دَخَلَ الْخَلاَءَ وَضَعَ خَاتَمَهُ  

"When the Messenger of Allah ﷺ entered the area in which he would relieve himself, he would remove the ring."  

كَانَ رَسُولُ اللَّهِ ﷺ إِذَا دَخَلَ الْخَلاَءَ نَزَعَ خَاتَمَهُ  

When the Prophet entered the toilet, he would take off his ring. (Using translation from Ibn Mājah 303)  

أَنَّ النَّبِيَّ ﷺ كَانَ «إِذَا دَخَلَ الْخَلَاءَ وَضَعَ خَاتَمَهُ»  

When entering the Khala', the Messenger of Allah [SAW] would take off his ring. (Using translation from Nasāʾī 5213)  

«أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ إِذَا دَخَلَ الْخَلَاءَ وَضَعَ خَاتَمَهُ»