Dua 140 ☆
There is not any slave of Allah who commits a sin, then he perfects his ablution and stands to pray two Rak'ahs of prayer, then seeks Allah's forgiveness, except that Allah will forgive him.
Reference: Abu Dawud 2/86, At-Tirmithi 2/257. Al-Albani graded it authentic in Sahih Abu Dawud 1/283.