Narrated from his father who said: "Al-Hasan and Al-Husain wore their ring on their left hand."

This Hadith is Hasan Sahih.
Jami` at-Tirmidhi Book 24, Hadith 24
← Previous Hadith "Ibn Abbas wore a ring on his right hand. And I do not doubt he said: 'I saw the Messenger of Allah (ﷺ) wearing a ring on his right hand.'"

Muhammad bin Isma'il said: "The Hadith is Muhammad bin Ishaq from As-Salt bin 'Abdullah bin Nawfal is a Hasan Sahih Hadith."

Jami` at-Tirmidhi Book 24, Hadith 23 Next Hadith → "I saw Ibn Rafi' said: "The Messenger of Allah (ﷺ) wore a ring on his right hand."

He said: Muhammad said: "This is the most correct thing related from the Prophet (ﷺ) on this topic."

Jami` at-Tirmidhi Book 24, Hadith 25