Chapter on I'tikaf (spiritual Retreat)
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 2|Chapter 38
وَ رَوَى اَلْحَسَنُ بْنُ مَحْبُوبٍ عَنْ عُمَرَ بْنِ يَزِيدَ قَالَ: قُلْتُ لِأَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ مَا تَقُولُ فِي اَلاِعْتِكَافِ بِبَغْدَادَ فِي بَعْضِ مَسَاجِدِهَا قَالَ «لاَ تَعْتَكِفْ إِلاَّ فِي مَسْجِدِ جَمَاعَةٍ قَدْ صَلَّى فِيهِ إِمَامٌ عَدْلٌ جَمَاعَةً وَ لاَ بَأْسَ بِأَنْ يُعْتَكَفَ فِي مَسْجِدِ اَلْكُوفَةِ وَ اَلْبَصْرَةِ وَ مَسْجِدِ اَلْمَدِينَةِ وَ مَسْجِدِ مَكَّةَ ».
Al-Hasan ibn Mahbub narrated from Umar ibn Yazid, who said: "I asked Abu Abdullah عليه السلام: 'What do you say about performing i'tikaf in Baghdad in some of its mosques?' Imam عليه السلام replied: 'Do not perform i'tikaf except in a congregational mosque where a just Imam has led the congregation in prayer. There is no harm in performing i'tikaf in the mosque of Kufa, the mosque of Basra, the mosque of Medina, and the mosque of Mecca.'"
- Ṣaḥīḥ al-Faqīh, p. 111