It is narrated from Sayyiduna Uqbah bin Amir al-Juhani (may Allah be pleased with him) that he went out with the Messenger of Allah (peace and blessings be upon him) in the Battle of Tabuk. (He said:) The duty of grazing the animals was upon me and a companion of mine. I saw the Messenger of Allah (peace and blessings be upon him) (free), and the people had gathered around him, so I said to my companion: Take over my work so that I can sit with the Messenger of Allah (peace and blessings be upon him) and hear from him. So I came to him (peace and blessings be upon him) and heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever performs ablution (wudu) and performs his ablution well, and prays two rak'ahs, turning to them with full attention, nothing distracting him, comes out of his sins as if his mother had just given birth to him."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15015