Narrated Ya'la bin Murrah:
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).] (IT)
English reference (IT): Vol. 1, Book 46, Hadith 3775 (IT)
Arabic reference (IT): Book 49, Hadith 4144 (IT)