I‘tikaf is not Valid without Fasting
Al-Kāfi|Volume 4|Book 2|Chapter 77
3ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ حَمَّادٍ عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَم) قَالَ لا اعْتِكَافَ إِلاَّ بِصَوْمٍ فِي الْمَسْجِدِ الْجَامِعِ.
3. Ali ibn Ibrahim has narrated from his father from ibn abu ‘ Umayr from Hammad from al-Halabiy who has said the following: “Abu ‘Abd Allah عليه السلام, has said, ‘There is no i'tikaaf except with fasting in the general Masjid.’”
- Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (16/427)
- Ṣaḥīḥ al-Kāfī