Sunan Ibn Majah

It was narrated from Anas bin Malik that :The Prophet said: ""Whoever performs ablution and does it well, then says three times: 'Ashhadu an la ilaha illallah wahdahu la sharika lahu, wa ashhadu anna Muhammadan `abduhu wa rasuluhu (I bear witness that none has the right to be worshipped but Allah alone, with no partner, and I bear witness that Muhammad is His slave and His Messenger),' eight gates of Paradise will be opened for him; whichever one he wants he may enter."" (Da'if) Another chain with similar wording