Mustahab

Mustahab means (something that is) liked and welcomed. They are the sunnahs that are less strong and the deeds that the Prophet occasionally did. Sunnahs and mustahabs are also called "nafilah" (supererogatory). Nafilah means extra or additional. That is, a person who performs a sunnah prayer does something additional to his main duty. For instance, an authorized person says to Ahmed, "Abdullah is a poor person. Give him a suit." Ahmed gives Abdullah a suit along with a shirt, sweater and socks in addition.

We can explain fard, wajib, sunnah and mustahab by giving the following example: The head and torso of a person can be likened to fard, his arms and legs to wajib, his ears, hair and nails to strong sunnah, his eyebrows  and body hair to less strong sunnah, the cleanliness and plainness of his color to mustahab. When this example is considered, the principles and pillars of worship are fard. A man without a head cannot exist as a man; similarly, a prayer without wudu, and prostration cannot be called a salah (prayer).