How was the founder and prophet of Islam, Muhammad, able to unify the peoples of Arabia, and set out on what would become a massive and rapid campaign of conquest in the 7th century?

I don't have a textbook for this course and I have researched this question but can't find a resource that goes into details. I can only gather that Muhammad used Islam to unite the people of Arabia but not how exactly. I'm looking for an answer that explains how the Arabian people were united by this.

3 answers

http://www.fsmitha.com/h3/h03is.htm
Thank you so much! That was really helpful.
You are very welcome.