صحیح ابن حبان
Ibn Hibban
كتاب الصوم
Book of Fasting
باب رؤية الهلال - ذكر البيان بأن قوله صلى الله عليه وسلم " فصوموا ثلاثين أراد به إن لم تروا الهلال
Chapter on Sighting the Crescent - Clarifying that “fast thirty days” means if the crescent is not seen
1 hadith
Hadith 3458
Sayyiduna Hudhayfah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "Do not begin the month until you see the new moon of the first (day), or complete the count of thirty (days). Then you should begin fasting, until when you see the new moon of the first (day) or complete the count (then observe Eid al-Fitr)."