Later , the practice of communal Friday prayers was developed .
Later , the practice of communal Friday prayers was became standard there - afterwards , by Ruhollah Khomeini in Iran and later by Mohammad Mohammad Sadeq al - Sadr in Iraq .
Later , the practice of communal Friday prayers was developed , and became standard there - afterwards , by Ruhollah Khomeini in Iran and later by Mohammad Mohammad Sadeq al - Sadr in Iraq .