Al-Kāfi - Volume 7 > One who has Testimony there is no Oath on Him
Hadith #1

1- عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ بَعْضِ أَصْحَابِهِ عَنْ عَاصِمِ بْنِ حُمَيْدٍ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ قَالَ سَأَلْتُ أَبَا جَعْفَرٍ (عَلَيْهِ السَّلام) عَنِ الرَّجُلِ يُقِيمُ الْبَيِّنَةَ عَلَى حَقِّهِ هَلْ عَلَيْهِ أَنْ يُسْتَحْلَفَ قَالَ لا.

1. Ali ibn Ibrahim has narrated from his father from certain persons of his people from ‘Asem ibn Humayd from Muhammad ibn Muslim who has narrated the following: “I once asked abu Ja‘far, ‘Alayhi al-Salam, about the case of a man who has testimony; if it is obligatory on him to take an oath. He (the Imam) said, ‘No, it is not obligatory on him/”