ENOfficial
Narrated Ja'far bin Muhammad : Narrated from his father who said: "Al-Hasan and Al-Husain wore their ring on their left hand." This Hadith is Hasan Sahih.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا حَاتِمُ بْنُ إِسْمَاعِيلَ، عَنْ جَعْفَرِ بْنِ مُحَمَّدٍ، عَنْ أَبِيهِ، قَالَ كَانَ الْحَسَنُ وَالْحُسَيْنُ يَتَخَتَّمَانِ فِي يَسَارِهِمَا . وَهَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ .
sunnah.com