Sahih al-Bukhari, Hadith 2791 ⓘ
Narrated Samura: The Prophet said, "Last night two men came to me (in a dream) and made me ascend a tree and then admitted me into a better and superior house, better of which I have never seen. One of them said, 'This house is the house of martyrs."
حَدَّثَنَا مُوسَى، حَدَّثَنَا جَرِيرٌ، حَدَّثَنَا أَبُو رَجَاءٍ، عَنْ سَمُرَةَ، قَالَ النَّبِيُّ صلى الله عليه وسلم " رَأَيْتُ اللَّيْلَةَ رَجُلَيْنِ أَتَيَانِي فَصَعِدَا بِي الشَّجَرَةَ، فَأَدْخَلاَنِي دَارًا هِيَ أَحْسَنُ وَأَفْضَلُ، لَمْ أَرَ قَطُّ أَحْسَنَ مِنْهَا قَالاَ أَمَّا هَذِهِ الدَّارُ فَدَارُ الشُّهَدَاءِ " .
also referenced under: Book 56, Hadith 9 (In-Book) & Volume 4, Book 52, Hadith 49 (USC-MSA)