In the hadith of Sayyiduna Ibn Umar and Anas (may Allah be pleased with them both) it is mentioned:
'Allahumma-j'alni mina-t-tawwabina wa-j'alni mina-l-mutatahhirin'
(O Allah, make me among those who repent much and make me among those who purify themselves.)
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 370