“What do you think about a man who committed a sin?”

وَمَن يَعۡمَلۡ سُوٓءًا أَوۡ يَظۡلِمۡ نَفۡسَهُ ۥ ثُمَّ يَسۡتَغۡفِرِ ٱللَّهَ يَجِدِ ٱللَّهَ غَفُورً۬ا رَّحِيمً۬ا
And whoever does evil or wrongs himself but afterwards seeks Allah’s Forgiveness, he will find Allah Oft¬Forgiving, Most Merciful.
[Surah AnNisa (4): 110]

It is reported that a man came to Ali and asked, What do you think about a man who committed a sin? He replied, He must seek Allāh’s forgiveness and repent to Him.

[The man] said, He did that, but then sinned again? [Ali] said, He must seek Allāh’s forgiveness and repent to Him. The man again said, He did that, but returned to sin. [Ali] said, He must seek Allāh’s forgiveness and repent to Him.

The man said for the fourth time, He did, but then sinned again. Ali then said, Until when? Then he said, He must seek Allāh’s forgiveness and repent to Him; and not give up until it is Shayṭān who is defeated [overcome].

Hunād b. Al-Sarī, Kitāb Al-Zuhd