اَللّٰهُمَّ اجْعَلْنِيْ مِنَ التَّوَّابِيْنَ وَاجْعَلْنِيْ مِنَ الْمُتَطَهِّرِيْنَ ـ

Allahummaj-‘alnii minat-tawwaabiina waj-‘alnii minal-mutatahhiriin. (‘Umar ibm al-Khattab. Sunan at-Tirmidhi #50)

O Allah, make me one of those who turn to You and repent much, and make me one of those who stay very clean and very pure.

This du’aa is also to be said after making wudu’.

(Source: Khalid Baig’s translation and commentary of du’aa #101 in the Accepted Whispers: Munajat-e-Maqbul)