It is narrated from Hibban bin al-Harith: We came to Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) while he was staying in the camp of Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him). I found him eating, and (on seeing us) he said: "Come near and eat." I said: (O Commander of the Believers!) I intend to fast. At that he said: "I too intend to fast." Then he ate, and when he had finished, he ordered his muezzin Ibn al-Nabbah: "Call the iqamah for the prayer."
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الصيام / 1059
Hadith Gradingمحدثین:إسناده حسن
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :إسناده حسن. » «أخرجه السنن الكبرى للبيهقي برقم: 1828، وأخرجه مصنف عبد الرزاق برقم: 7609»