Al-Kāfi - The Book of Fasting

َّدٍ عَنْ صَالِحِ بْنِ أَبِي حَ٠َّادٍ عَنِ ابْنِ سِنَانٍ عَنْ حُذَيْفَةَ بْنِ ٠َنْصُورٍ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَ٠) قَالَ شَهْرُ رَ٠َضَانَ ثَلاثُونَ يَوْ٠اً لا يَنْقُصُ أَبَداً.

وَعَنْهُ عَنِ الْحَسَنِ بْنِ الْحُسَيْنِ عَنِ ابْنِ سِنَانٍ عَنْ حُذَيْفَةَ ٠1.

Ali ibn Muhammad has narrated from Salih ibn abu Hammad from ibn Sinan from Hudhayfah ibn Mansur who has said the following: “Abu ‘ Abd Allah (a.s.), has said, ‘The month of Ramadan is thirty days and it never is less.”’ (Fatwa best explains this Hadith, however according to science, a lunar (synodic) month is 29 days, 12 hours, and approximately 44 minutes) It is narrated from him (narrator of previous Hadith) from al-Hassan ibn al-Husayn from ibn Sinan from Hudhayfah a similar Hadith.

السندان ضعيفان - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (16/231))