Fath al-Rabbani

It is narrated from Sayyiduna Uthman bin Affan (may Allah be pleased with him) that he called for water and performed ablution, rinsed his mouth, put water into his nose, then washed his face three times, washed his arms three times, then wiped over his head and the outer part of his feet, and then he laughed and said to his companions: "Will you not ask me about the thing that made me laugh?" The people said: "O Commander of the Faithful! Why did you laugh?" He said: "I saw the Messenger of Allah (peace and blessings be upon him) call for water while he was near this very place, and he performed ablution just as I have done, then he smiled and said: 'Will you not ask me about the thing that made me smile?' The people said: 'O Messenger of Allah! What made you laugh?' He (peace and blessings be upon him) said: 'Indeed, when a servant calls for water for ablution and washes his face, Allah Almighty removes from his face every sin which his face committed; then when he washes his arms, the same happens; when he wipes (his head), the same happens; and when he washes his feet, the same happens.'"