(Disregarding this principle) Thamud rejected (Saleh) while playing God. ('Tagha' = Being 'Taghut' = Becoming a false god = Playing God = Transgressing = Rebelling = Crossing bounds of decency = Extreme arrogance)
Thamood (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)