Al-Kāfi - Volume 7 > Testimony of a Blind and Speechless
Hadith #3

3- عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ سَهْلِ بْنِ زِيَادٍ عَنْ إِسْمَاعِيلَ بْنِ مِهْرَانَ عَنْ دُرُسْتَ عَنْ جَمِيلٍ قَالَ سَأَلْتُ أَبَا عَبْدِ اللهِ (عَلَيْهِ السَّلام) عَنْ شَهَادَةِ الأصَمِّ فِي الْقَتْلِ قَالَ يُؤْخَذُ بِأَوَّلِ قَوْلِهِ وَلا يُؤْخَذُ بِالثَّانِي.

3. A number of our people have narrated from Sahl ibn Ziyad from ’Isma‘il ibn Mehran from Durust from Jamil who has narrated the following: “I once asked abu ‘Abd Allah, ‘Alayhi al-Salam, about the testimony of a speechless man in the case of murder. He (the Imam) said, ‘His first words are admissible and his second words are not admissible.”’