Sunan an-Nasa'i, Volume 2, Book 14, Hadith 1414 (DarusSalam)

It was narrated from 'Abdullah bin Buraidah that: His father said: "The Prophet was preaching, then Al-Hasan and Al-Husain came, wearing red shirts and stumbling in them. The Prophet came down, interrupting himself, and picked them up, then he went back to the minbar and said: 'Allah has spoken the truth: Your wealth and your children are only a trial. I saw these two stumbling in their shirts and I could not continue until I had interrupted myself and picked them up.'"

أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الْعَزِيزِ، قَالَ حَدَّثَنَا الْفَضْلُ بْنُ مُوسَى، عَنْ حُسَيْنِ بْنِ وَاقِدٍ، عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ، عَنْ أَبِيهِ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يَخْطُبُ فَجَاءَ الْحَسَنُ وَالْحُسَيْنُ - رضى الله عنهما - وَعَلَيْهِمَا قَمِيصَانِ أَحْمَرَانِ يَعْثُرَانِ فِيهِمَا فَنَزَلَ النَّبِيُّ صلى الله عليه وسلم فَقَطَعَ كَلاَمَهُ فَحَمَلَهُمَا ثُمَّ عَادَ إِلَى الْمِنْبَرِ ثُمَّ قَالَ ‏"‏ صَدَقَ اللَّهُ ‏{‏ إِنَّمَا أَمْوَالُكُمْ وَأَوْلاَدُكُمْ فِتْنَةٌ ‏}‏ رَأَيْتُ هَذَيْنِ يَعْثُرَانِ فِي قَمِيصَيْهِمَا فَلَمْ أَصْبِرْ حَتَّى قَطَعْتُ كَلاَمِي فَحَمَلْتُهُمَا ‏"‏ ‏.‏

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also referenced under: Book 14, Hadith 1424 (In-Book)