Islamic law collects the best of everything, so its rules are in harmony with pure human nature, including rules caring about internal and external human cleanliness. In this hadith, Anas ibn Malik narrated that the Prophet (as in Abu Dawud's and Al-Nasa’i's narration) talked about four issues that a Muslim was not allowed to leave for more than forty days. (1) Trimming the mustache: A Muslim should trim the hair growing on the upper lip. In the Two Sahihs, Ibn Omar narrated that the Prophet said, "Do the opposite of what the polytheists do. Let the beard grow long and clip the mustache." (2) Trimming the nails: This is because they contain dirties that prevent water during purification and ablution. (3) Plucking armpit hair: This is because its smell stinks due to sweat if it is uncut for a long time. Plucking is better if one bears it but removing it by any means is allowable. (4) Shaving the pubic hair: It is the hair growing around one's private parts. Finally, a Muslim is not allowed to leave them for more than forty days. However, it is better to cut them before. Adhering to these acts of cleanliness leads to protect one's body from filth and beautify its outer appearance. Thus, a Muslim combines internal and external cleanliness and purity..