Simplify the following text for a Grade 11 native English-speaking person.
Original: Shi ` as view that Ali , the prophet of Islam 's son-in-law and the progenitor of Muhammad 's only continuing lineage , was given the title during Muhammad 's era .
Simplified: Shi ` a view that Ali , the prophet of Islam 's son-in-law and the only person to father the prophets only continuing lineage , was given the title during Muhammad 's era .