Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
nasai-kubra:3212Ismāʿīl b. Masʿūd > Khālid > Shuʿbah > Yazīd b. Abū Ziyād > Miqsam > Ibn ʿAbbās

[Machine] The Messenger of Allah ﷺ observed I'tikaf while fasting. Muhammad bin Jafar compiled both narrations.  

الكبرى للنسائي:٣٢١٢أَخْبَرَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ قَالَ حَدَّثَنَا خَالِدٌ عَنْ شُعْبَةَ عَنْ يَزِيدَ بْنِ أَبِي زِيَادٍ عَنْ مِقْسَمٍ عَنِ ابْنِ عَبَّاسٍ قَالَ

«احْتَجَمَ رَسُولُ اللهِ ﷺ وَهُوَ صَائِمٌ» جَمَعَ الْحَدِيثَيْنِ مُحَمَّدُ بْنُ جَعْفَرٍ