Sahih al-Bukhari 3691Book 62, Hadith 41
حَدَّثَنَا يَحْيَى بْنُ بُكَيْرٍ، حَدَّثَنَا اللَّيْثُ، عَنْ عُقَيْلٍ، عَنِ ابْنِ شِهَابٍ، قَالَ أَخْبَرَنِي أَبُو أُمَامَةَ بْنُ سَهْلِ بْنِ حُنَيْفٍ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ ـ رضى الله عنه ـ قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ " بَيْنَا أَنَا نَائِمٌ رَأَيْتُ النَّاسَ عُرِضُوا عَلَىَّ وَعَلَيْهِمْ قُمُصٌ، فَمِنْهَا مَا يَبْلُغُ الثَّدْىَ، وَمِنْهَا مَا يَبْلُغُ دُونَ ذَلِكَ، وَعُرِضَ عَلَىَّ عُمَرُ وَعَلَيْهِ قَمِيصٌ اجْتَرَّهُ ". قَالُوا فَمَا أَوَّلْتَهُ يَا رَسُولَ اللَّهِ قَالَ " الدِّينَ ".
I heard Allah's Messenger (ﷺ) saying, "While I was sleeping, the people were presented to me (in a dream). They were wearing shirts, some of which were merely covering their (chests). and some were a bit longer. `Umar was presented before me and his shirt was so long that he was dragging it." They asked, "How have you interpreted it, O Allah's Messenger (ﷺ)?" He said, "Religion."