: Indeed he succeeds who purifies his ownself (i.e. obeys and performs all that Allah ordered, by following the true Faith of Islamic Monotheism and by doing righteous good deeds).
: And indeed he fails who corrupts his ownself (i.e. disobeys what Allah has ordered by rejecting the true Faith of Islamic Monotheism or by following polytheism, etc. or by doing every kind of evil wicked deeds).
: Thamud (people) denied (their Prophet) through their transgression (by rejecting the true Faith of Islamic Monotheism, and by following polytheism, and by committing every kind of sin).