Congregational Prayer and Its Virtue
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 57
وَ سَأَلَ عَلِيُّ بْنُ جَعْفَرٍ أَخَاهُ مُوسَى بْنَ جَعْفَرٍ عَلَيْهِمَا اَلسَّلاَمُ: عَنِ اَلْمَرْأَةِ تَؤُمُّ اَلنِّسَاءَ مَا حَدُّ رَفْعِ صَوْتِهَا بِالتَّكْبِيرِ وَ اَلْقِرَاءَةِ فَقَالَ «قَدْرُ مَا تُسْمِعُ.
Ali ibn Ja'far was asked about his brother Imam Musa ibn Jafar Al-Kadhim عليه السلام about a woman leading other women in prayer: "What is the limit of raising her voice in the takbir (saying 'Allahu Akbar') and in recitation?" Imam عليه السلام replied: "To the extent that they can hear her."
- Ṣaḥīḥ al-Faqīh