Sahih al-Bukhari, Book 62, Hadith 42 (In-Book) ⓘ

Narrated Abu Sa`id Al-Khudri: I heard Allah's Messenger 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?" He said, "Religion."

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 ‏"‏‏.‏