Surah At-Taubah, Ayat 108

Ayat 108. Never stand you therein. Verily, the mosque whose foundation was laid from the first day on piety is more worthy that you stand therein (to pray). In it are men who love to clean and to purify themselves. And Allah loves those who make themselves clean and pure (i.e. who clean their private parts with dust [i.e. to be considered as soap) and water from urine and stools, after answering the call of nature]. 

Hazrat Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah  [SAWW](PBUH) said, "When a Muslim, or a believer, washes his face (in the course of Wudu'), every sin which he committed with his eyes, will be washed away from his face with water, or with the last drop of water; when he washes his hands, every sin which is committed by his hands will be effaced from his hands with the water, or with the last drop of water; and when he washes his feet, every sin his feet committed will be washed away with the water, or with the last drop of water; until he finally emerges cleansed of all his sins.'' [Muslim Hadith # 0475]. 

Lesson : as mentioned above in Surah At-Taubah Ayat 108 "And Allah loves those who make themselves clean and pure". This Hadith has the same meaning mentioned in the preceding Ahadith. That is to say, such minor sins are washed off by Wudu'. In other words, Wudu' is a means of purification of the body as well as the soul.