Chapter on the Etiquettes of Judgment
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 1|Chapter 10
وَ رَوَى مُحَمَّدُ بْنُ مُسْلِمٍ عَنْ أَبِي جَعْفَرٍ عَلَيْهِ اَلسَّلاَمُ قَالَ: "قَضَى رَسُولُ اَللَّهِ صَلَّى اَللَّهُ عَلَيْهِ وَ آلِهِ أَنْ يُقَدَّمَ صَاحِبُ اَلْيَمِينِ فِي اَلْمَجْلِسِ بِالْكَلاَمِ".
Muhammad ibn Muslim narrated from Abu Jafar Imam Muhammad ibn Ali Al-Baqir عليه السلام who said: "The Messenger of Allah سبحانه وتعالى (peace be upon him and his family) ruled that the one on the right should speak first in a gathering."
- Ṣaḥīḥ al-Faqīh, p. 184