Upon completing the ablution

أَشْهَدُ أَنْ لا إِلَـهَ إِلاّ اللهُ وَحْدَهُ لا شَريـكَ لَـهُ وَأَشْهَدُأَنَّ مُحَمّـداً عَبْـدُهُ وَرَسـولُـه

I bear witness that none has the right to be worshipped but Allah alone, Who has no partner; and I bear witness that Muhammad is His slave and His Messenger.

Muslim 1/209.

اللّهُـمَّ اجْعَلنـي مِنَ التَّـوّابينَ وَاجْعَـلْني مِنَ المتَطَهّـرين.

O Allah, make me among those who turn to You in repentance, and make me among those who are purified.

At-Tirmidhi 1/78. See also Al-Albani, Sahih At- Tirmidhi 1/18

سُبْحـانَكَ اللّهُـمَّ وَبِحَمدِك أَشْهَـدُ أَنْ لا إِلهَ إِلاّ أَنْتَ أَسْتَغْفِرُكَ وَأَتوبُ إِلَـيْك

Glory is to You, O Allah, and praise; I bear witness that there is none worthy of worship but You. I seek Your forgiveness and turn to You in repentance.

An-Nasa'i, 'Amalul-Yawm wal-Laylah, p. 173. See also Al-Albani, 'Irwa'ul-Ghalil 1/135 and 2/94.