Is one rewarded for abandoning masturbation, enduring it due to an oath taken by Allah to abandon it?

If the speech occurs within the soul without being uttered, it is not considered an oath. If the formula is pronounced by moving the tongue without an audible sound, it is not considered an oath by the majority of scholars, while the Malikis and those who agree with them consider it an oath. There is no evidence for a reward for this oath; what is required is repentance and abandonment of the bad habit. Patience in refraining from disobedience carries a great reward, and some scholars may even prefer it over patience in obeying God.