Ruling on shaving the head and the Sunnah regarding armpit hair

Question:
Is there any evidence, or anything that encourages shaving the head?

Answer:
Shaving the head is permissible. The Prophet (peace and blessings be upon him) said regarding the head: When he saw a man who had shaved part of his head, which is called al-qaza', he said: The Prophet (peace and blessings be upon him) shaved his head during Hajj. So, there is nothing wrong with shaving, or growing it out if one is able to grow it out in a manner that is in accordance with the Shari'ah, in order to follow the example of the Prophet (peace and blessings be upon him); there is nothing wrong with that. Now, if one is able to do so and takes care of it, not for the purpose of corruption, or for women, or the like of that, then there is no blame on him. And if he shaves it, there is nothing wrong with that.
As for the armpits, the Sunnah is to remove the armpit hair by plucking; this is the best. Likewise, the pubic hair is to be shaved, the nails are to be trimmed, and the mustache is to be cut. This is a Sunnah, and it may even become obligatory if it grows long. The Prophet (peace and blessings be upon him) said: He commanded the plucking of armpit hair, the shaving of pubic hair, and the trimming of nails for men and women. This is general for both men and women. It is prescribed for everyone to trim the nails, pluck the armpit hair, and shave the pubic hair. This is for everyone, and cutting the mustache is for men.