Chapter on Precaution in Giving Testimony
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 1|Chapter 31
وَ رُوِيَ عَنْ عُمَرَ بْنِ يَزِيدَ قَالَ: قُلْتُ لِأَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ رَجُلٌ يُشْهِدُنِي عَلَى اَلشَّهَادَةِ فَأَعْرِفُ خَطِّي وَ خَاتَمِي وَ لاَ أَذْكُرُ مِنَ اَلْبَاقِي قَلِيلاً وَ لاَ كَثِيراً فَقَالَ "إِذَا كَانَ صَاحِبُكَ ثِقَةً وَ مَعَكَ رَجُلٌ ثِقَةٌ فَاشْهَدْ لَهُ".
It is narrated from Umar ibn Yazid, who said: I said to Abu Abdullah عليه السلام: "A man calls me to testify, and I recognize my handwriting and my seal, but I do not remember anything else, whether little or much." Imam عليه السلام said: 'If your companion is trustworthy and you have another trustworthy man with you, then testify for him.'"
- Ṣaḥīḥ al-Faqīh, p. 191