Man Lā Yaḥḍuruh al-Faqīh
Hadith 3441915 - وَ سَأَلَ عَلِيُّ بْنُ جَعْفَرٍ أَخَاهُ مُوسَى بْنَ جَعْفَرٍ عَلَيْهِمَا اَلسَّلاَمُ : عَنِ اَلرَّجُلِ يَرَى اَلْهِلاَلَ فِي شَهْرِ رَمَضَانَ وَحْدَهُ لاَ يُبْصِرُهُ غَيْرُهُ أَ لَهُ أَنْ يَصُومَ قَالَ «إِذَا لَمْ يَشُكَّ فَلْيُفْطِرْ وَ إِلاَّ فَلْيَصُمْهُ مَعَ اَلنَّاسِ.
Hadith.1915 - Ali ibn Ja'far asked his brother Imam Musa ibn Jafar Al-Kadhim (as) about a man who sees the crescent for the Month of Ramadan alone, and no one else sees it. Should he fast?
Imam (as) said: "If he has no doubt, let him break his fast. Otherwise, let him fast with the people."