The most accurate response is: During the hijra, Muhammad created rules that governed and united Muslims.
The hijra, which is the migration of Muhammad and his followers from Mecca to Yathrib (later known as Medina) in 622 CE, marked a significant turning point in the development of Islam. In Medina, Muhammad established a community of Muslims, created governance structures, and set forth rules and guidelines that would help unify the Muslim community, allowing Islam to grow and flourish.