ENOfficial
Nafi' said that Ibn 'Umar used to wear his signet-ring on his left hand.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا هَنَّادٌ، عَنْ عَبْدَةَ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، أَنَّ ابْنَ عُمَرَ، كَانَ يَلْبَسُ خَاتَمَهُ فِي يَدِهِ الْيُسْرَى .
sunnah.com