The Prophet Muhammad (S.A.W.) stated that “these two [Hassan & Hussain] are the swords of the heavens.” He has also stated that, “Hussain is from me and I am from Hussain. May Allah keep him as a friend who keeps Hussain as his friend. Hussain is a grandchild from among grandchildren.”
[Sunan al-Tirmidhi, Hadith no. 3800, Vol. 5, Page 429].