كتاب الْمَسَاجِدِ وَمَوَاضِعِ الصَّلاَةِ
5  
The Book of Mosques and Places of Prayer
(39)
Chapter: The time of `Isha and delaying it
(39)
باب وَقْتِ الْعِشَاءِ وَتَأْخِيرِهَا ‏
Sahih Muslim 640 b

Anas b. Malik reported:

We waited for the Messenger of Allah (may peace be upon hi n) one night, till it was about midnight. He (the Holy Prophet) came and observed prayer and then turned his face towards us, as it I was seeing the lustre of the silver ring on his finger.
وَحَدَّثَنِي حَجَّاجُ بْنُ الشَّاعِرِ، حَدَّثَنَا أَبُو زَيْدٍ، سَعِيدُ بْنُ الرَّبِيعِ حَدَّثَنَا قُرَّةُ بْنُ خَالِدٍ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ نَظَرْنَا رَسُولَ اللَّهِ صلى الله عليه وسلم لَيْلَةً حَتَّى كَانَ قَرِيبٌ مِنْ نِصْفِ اللَّيْلِ ثُمَّ جَاءَ فَصَلَّى ثُمَّ أَقْبَلَ عَلَيْنَا بِوَجْهِهِ فَكَأَنَّمَا أَنْظُرُ إِلَى وَبِيصِ خَاتَمِهِ فِي يَدِهِ مِنْ فِضَّةٍ ‏.‏
Reference : Sahih Muslim 640b
In-book reference : Book 5, Hadith 282
USC-MSA web (English) reference : Book 4, Hadith 1337
  (deprecated numbering scheme)