Chapter on I'tikaf (spiritual Retreat)
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 2|Chapter 38
وَ رَوَى اَلْحَسَنُ بْنُ اَلْجَهْمِ عَنْ أَبِي اَلْحَسَنِ عَلَيْهِ اَلسَّلاَمُ قَالَ: سَأَلْتُهُ عَنِ اَلْمُعْتَكِفِ يَأْتِي أَهْلَهُ قَالَ «لاَ يَأْتِي اِمْرَأَتَهُ لَيْلاً وَ لاَ نَهَاراً وَ هُوَ مُعْتَكِفٌ ».
It is narrated by Al-Hasan ibn Al-Jahm, from Abu Al-Hasan عليه السلام, who was asked about a person performing i'tikaf engaging in relations with their spouse. Imam عليه السلام said: "They must not approach their wife, neither by night nor by day, while they are in i'tikaf."
- Ṣaḥīḥ al-Faqīh