Chapter on Itikaf and What Fasting Is Obligatory in It
Tahdhīb al-Aḥkām|Volume 4|Book 2|Chapter 27
وَعَنْهُ عَنِ اَلْعَبَّاسِ بْنِ عَامِرٍ عَنْ عَبْدِ اَللَّهِ بْنِ بُكَيْرٍ عَنْ عُبَيْدِ بْنِ زُرَارَةَ قَالَ قَالَ أَبُو عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ:» لاَ يَكُونُ اَلاِعْتِكَافُ إِلاَّ بِصَوْمٍ«.
And from him, from al-Abbas ibn Amir, from Abdullah ibn Bukayr, from Ubayd ibn Zurarah, who said:
Abu Abdillah عليه السلام, peace be upon him, said: “There is no seclusion (itikaf) except with fasting.”
- Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 4, p. 361
- Ṣaḥīḥ al-Tahdhīb, p. 378