dua for When completing ablution

1)

أَشْهَدُ أَنْ لَا إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ
Ashhadu an la ilaha illal-lahu wahdahu la shareeka lah, wa-ashhadu anna Muhammadan AAabduhu warasooluh.
I bear witness that none has the right to be worshipped except Allah, alone without partner, and I bear witness that Muhammad is His slave and Messenger.
Sahih Muslim: 234 (b)
Reference
Translation

2)

أَشْهَدُ أَنْ لَا إِلَهَ إِلاَّ اللَّهُ وَحْدَهُ لاَ شَرِيكَ لَهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ، اللَّهُمَّ اجْعَلْنِي مِنَ التَّوَّابِينَ وَاجْعَلْنِي مِنَ الْمُتَطَهِّرِينَ
Ashhadu an la ilaha illallah, wahdahu la sharika lahu, wa ashhadu anna Muhammadan-abduhu wa rasuluhu, Allahummajalni minat tawwabin, waj'alni minal mutatahhirin.
Translation
I bear witness that none has the right to be worshipped except Allah, alone without partner, and I bear witness that Muhammad is His slave and Messenger. O Allah, make me of those who return to You often in repentance and make me of those who remain clean and pure.
Reference
At-Tirmidhi: 55