Tafsir of Al-`Ankabut 29:6

(And whoever strives) in the obedience of Allah, the Almighty and Majestic, (then he only strives for his own soul), because the benefit of the reward prepared for that action returns to it. (Indeed, Allah is free from need of the worlds); therefore, He has no need for their obedience. He, the Glorified, only commanded them to it as a means of exposing them to the reward, in accordance with His mercy and His wisdom.