Greetings
For orthodox muslims, the Qur'an is the primary book for spirtual guidance. Orthodox Muslms do get inspiration from a supplementary source called the Hadith. The Hadith is the oral tradition of early muslims, including the Prophet Mohammad. There is some debate whether some of the writings attibuted to the prophet was actually his.

But that is another story.

You can define Rastafari in any way that you wish. Faith is personal. You just have to overstand that everyone may not sight Rastafari from the same perspective as the I.

I would think that it would be proper for the man whom a faith/religion is named after, to be in accord with "principles" of that said faith/religion that carries his name.

Dont you?

Peace