Importance of Ablution ( Wudhu)
It was narrated that ‘Umar bin Al-Khattab may ALLAH be pleased with him said: “The Messenger of Allah peace be upon him said: whoever performs Wudhu well, then says: 
Ashhadu alla ilaha ilAllahu, wa ash-hadu anna muhammadan abduhu wa rasuluhu (I bear witness that there is no God except Allah, and I bear witness that Muhammad is the slave and Messenger of Allah Then eight gates of Paradise will be opened for him, and he may enter through whichever one he wishes
Sunan nasaii, Vol1, 148 – Sahih
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Abu Huraira Radhi allahu anhu reported:
Allah’s Messenger Sal-Allahu Alaihi Wasallam said: When a bondsman-a Muslim or a believer-washes his face (in course of ablution), every sin he contemplated with his eyes, will be washed away from his face along with water, or with the last drop of water; when he washes his hands, every sin they wrought will be effaced from his hands with the water, or with the last drop of water; and when he washes his feet, every sin towards which his feet have walked will be washed away with the water or with the last drop of water with the result that he comes out pure from all sins.
Sahih Muslim, Book 1, Hadith 475