Khwaja Moinu'd-Din Chishti (Gareeb Nawaaz Ajmer) says:

"SHAH AST HUSAIN, BADSHAH AST HUSAIN
DEEN AST HUSAIN ,DEEN PANAH AST HUSAIN,
SARDAAD ,NA DAAD DAST DAR DAST-E YAZEED,
HAQQUAA KE BINA-E LA ILAH AST HUSAIN."

{Husain is Shah (spiritual leader), Husain is Badshah (the administrative leader or the king) of this world. Husain is himself "religion" and also the one who gave shelter to the religion. He preferred to give his head but not his hand to Yazeed. The fact is ...Husain is the foundation of The Religion, the foundation of la ilah ilallah}