O you who believe! Fear God and believe in His Messenger and He will bestow upon you a double portion of His Mercy; He will provide for you a Light by which you will walk.
I am leaving among you two matters of great weight (al-thaqalayn), the Book of Allah and my kindred (itrati), the People of my House (Ahl al-Bayti), and these two shall never be separated until they return to me at the Pool [of Kawthar in Paradise on the Day of Judgement].
–Prophet Muhammad (s.a.s.) – Muslim Societies and Civilisations Volume 1 – Page 88