Abu Dawud said: Ibn Ishaq and Usamah b. Zaid transmitted from Nafi': "On his right hand".
In-book : Book 36, Hadith 14
English translation : Book 35, Hadith 4215
36. Signet-Rings (Kitab Al-Khatam)
باب مَا جَاءَ فِي التَّخَتُّمِ فِي الْيَمِينِ أَوِ الْيَسَارِ