that the Messenger of Allah (ﷺ) said: "Husain is from me, and I am from Husain. Allah loves whoever loves Husain. Husain is a Sibt among the Asbat." [Asbat, plural of Sibt: A great tribe. Meaning, Al-Husain would have many offspring, such that they would become a great tribe. And this has indeed occurred. See Tuhfat Al-Ahwadhi (4/341).]
حَدَّثَنَا الْحَسَنُ بْنُ عَرَفَةَ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ عَيَّاشٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُثْمَانَ بْنِ خُثَيْمٍ، عَنْ سَعِيدِ بْنِ رَاشِدٍ، عَنْ يَعْلَى بْنِ مُرَّةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم حُسَيْنٌ مِنِّي وَأَنَا مِنْ حُسَيْنٍ أَحَبَّ اللَّهُ مَنْ أَحَبَّ حُسَيْنًا حُسَيْنٌ سِبْطٌ مِنَ الأَسْبَاطِ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ وَإِنَّمَا نَعْرِفُهُ مِنْ حَدِيثِ عَبْدِ اللَّهِ بْنِ عُثْمَانَ بْنِ خُثَيْمٍ وَقَدْ رَوَاهُ غَيْرُ وَاحِدٍ عَنْ عَبْدِ اللَّهِ بْنِ عُثْمَانَ بْنِ خُثَيْمٍ .
Tirmizi
Chapters on Virtues • Hadith 4012