Follow instructions carefully when performing rituals such as wudoo'.

This hadith teaches us the importance of cleanliness and ritual in Islam. It is narrated from Umar bin al khattab that he saw the Messenger of Allah performing wudoo', which is a ritual ablution done before prayer or other religious activities. He washed each part once as instructed by the Prophet Muhammad. This hadith emphasizes the importance of following instructions and being mindful of our actions when it comes to religious practices. It also shows us that cleanliness is an important part of our faith and should not be taken lightly.