اللَّهُمَّ اجْعَلْنِي مِنَ التَّوَّابِينَ وَاجْعَلْنِي مِنَ الْمُتَطَهِّرِينَ
Allahumma-j'alni minat-tawwabina waj'alni minal-mutatahhirin
Ee Allah, nifanye miongoni mwa wanaotubu na unifanye miongoni mwa wanaojitakasa.
Say after completing wudu, following the shahada
This dua asks Allah to make you among those who constantly seek forgiveness and purification.