Sahih Bukhari Volume 1, Book 11, Hadith Number 630

Narated By Humaid : Anas was asked, “Did Allah’s Apostle wear a ring?” He said, “Yes. Once he delayed the ‘Isha’ prayer till mid-night and after the prayer, he faced us and said, ‘The people prayed and have slept and you remained in prayer as long as you waited for it.’ ” Anas added, “As if I were just now observing the glitter of his ring.”