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The Prophet ﷺ said:
مَا مِنْ عَبْدٍ يُذْنِبُ ذَنْبًا فَيُحْسِنُ الطُّهُورَ ثُمَّ يَقُومُ فَيُصَلِّي رَكْعَتَيْنِ ثُمَّ يَسْتَغْفِرُ اللَّهَ إِلاَّ غَفَرَ اللَّهُ لَهُ
Ma min 'abdin yudhnibu dhanban fayuhsinut-tuhura thumma yaqumu fayusalli rak'atayni thumma yastaghfirullaha ila ghafarallahu lah
There is no servant who commits a sin, then purifies himself well, then stands and prays two rakʿahs, then asks Allah's forgiveness, except that Allah forgives him.
Source Sunan Abī Dāwūd 1521 Ṣaḥīḥ · Jāmiʿ at-Tirmidhī 406 (similar wording) Ḥasan
Compiler cites Abū Dāwūd 2/86; at-Tirmidhī 2/257; see al-Albānī, Ṣaḥīḥ Abī Dāwūd 1/283 (ṣaḥīḥ)