Nasrudin didn't part with his ring because he was attached to it, which the story clearly identifies as "an ordinary vice." Though as a teacher, Nasrudin may have taught his student a valuable lesson in non-attachment, Nasrudin himself was caught up in materialist attachment. This demonstrates two things: (1) we often know the best answers but fail to heed them ourselves; (2) we can be a positive influence for others even when we ourselves are less than perfect in our own adherence to the truths we that we espouse.
On Jul 1, 2025 Brian Besser wrote on Who Is Having This Pain?, by Mingyur Rinpoche: