Prohibition on Speaking without Knowledge.
Al-Kāfi|Volume 1|Book 2|Chapter 11
2ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ مُحَمَّدِ بْنِ عِيسَى بْنِ عُبَيْدٍ عَنْ يُونُسَ بْنِ عَبْدِ الرَّحْمَنِ عَنْ عَبْدِ الرَّحْمَنِ بْنِ الْحَجَّاجِ قَالَ قَالَ لِي أَبُو عَبْدِ الله (عَلَيْهِ السَّلام) إِيَّاكَ وَخَصْلَتَيْنِ فَفِيهِمَا هَلَكَ مَنْ هَلَكَ إِيَّاكَ أَنْ تُفْتِيَ النَّاسَ بِرَأْيِكَ أَوْ تَدِينَ بِمَا لا تَعْلَمُ.
2. Ali ibn Ibrahim has narrated from Muhammad ibn ‘Isa ibn ‘Ubayd from Yunus ibn ’Abd al-Rahman from ’Abd al-Rahman ibn al-Hajjaj who has said the following. “Imam abu ‘Abdallah عليه السلام has said, ‘Beware of two forms of behavior. It is such behaviors that have lead many people to their destruction. Beware of giving fatwa to people on the basis of your own opinion and to follow a religion without knowledge.’”
- Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (1/136)
- Ṣaḥīḥ al-Kāfī