Dua and dhikr after performing the wudu
Messenger of Allah ﷺ said: Whoever performs wudu, and performs the wudu well, then says:
ash-hadu an lā ilāha illa Allāh, waḥdahū lā sharīka lahū, wa-ash-hadu anna muḥammadan ʿabduhū wa-rasuluhu; Allāhumma jaʿalnī min al-tawwābīn wa-jaʿalnī min al-mutaṭahhirīn
(I testify that none has the right to be worshipped but Allah alone, who ha no partners, and I testify that Muhammad is His servant and Messenger; O Allah! Make me among those who constantly repent, and make me among those who thoroughly purify themselves.)
... then eight gates of Paradise are opened for him, that he may enter by whichever of them he wishes.
قَالَ رَسُولُ اللَّهِ ﷺ مَنْ تَوَضَّأَ فَأَحْسَنَ الْوُضُوءَ ثُمَّ قَالَ:
(أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ، وَحْدَهُ لاَ شَرِيكَ لَهُ، وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ؛ اللَّهُمَّ اجْعَلْنِي مِنَ التَّوَّابِينَ وَاجْعَلْنِي مِنَ الْمُتَطَهِّرِينَ)
فُتِحَتْ لَهُ ثَمَانِيَةُ أَبْوَابِ الْجَنَّةِ يَدْخُلُ مِنْ أَيِّهَا شَاءَ