The Book of Purification
1/109. Chapter:
What To Say After Finishing Wudu'
Sunan an-Nasai
أَخْبَرَنَا مُحَمَّدُ بْنُ عَلِيِّ بْنِ حَرْبٍ الْمَرْوَزِيُّ، قَالَ حَدَّثَنَا زَيْدُ بْنُ الْحُبَابِ، قَالَ حَدَّثَنَا مُعَاوِيَةُ بْنُ صَالِحٍ، عَنْ رَبِيعَةَ بْنِ يَزِيدَ، عَنْ أَبِي إِدْرِيسَ الْخَوْلاَنِيِّ، وَأَبِي، عُثْمَانَ عَنْ عُقْبَةَ بْنِ عَامِرٍ الْجُهَنِيِّ، عَنْ عُمَرَ بْنِ الْخَطَّابِ، - رضى الله عنه - قَالَ قَالَ رَسُولُ اللَّهِ " مَنْ تَوَضَّأَ فَأَحْسَنَ الْوُضُوءَ ثُمَّ قَالَ أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ فُتِّحَتْ لَهُ ثَمَانِيَةُ أَبْوَابِ الْجَنَّةِ يَدْخُلُ مِنْ أَيِّهَا شَاءَ " .
It was narrated that 'Umar bin Al-Khattab said: "The Messenger of Allah (ﷺ) said: 'Whoever performs Wudu' and does it well, then says: "Ashhadu an la ilaha ill-Allah was ashhadu anna Muhammadan 'abduhu wa rasuluh (I bear witness that there is none worthy of worship except Allah, and I bear witness that Muhammad is his slave and Messenger)," eight gates of Paradise will be opened for him, and he may enter through whichever one he wishes.'"
Reference : Sunan an-Nasa'i 148In-book reference : Book 1, Hadith 149English translation : Vol. 1, Book 1, Hadith 148