Chapter: The characteristics of the fitrah
Abu Huraira reported:
The Messenger of Allah (ﷺ) said: Trim closely the moustache, and grow beard, and thus act against the fire-worshippers. - Sahih:Muslim:260 (islam)

-Is it about the Zoroastrians, were they wearing only mustaches?
- Is it valid today, since muslim couldn't be mistaken for a Zoroastrian anymore (in Europe at last)?

Chapter: The clipping of nails
Narrated Nafi`:
Ibn `Umar said, The Prophet (ﷺ) said, 'Do the opposite of what the pagans do. Keep the beards and cut the moustaches short.' Whenever Ibn `Umar performed the Hajj or `Umra, he used to hold his beard with his hand and cut whatever remained outside his hold. - Sahih:Al Bukhari:5892 (islam)

-Is this why we have so much bearded men with no mustaches?

Chapter: The characteristics of the fitrah
'A'isha reported:
The Messenger of Allah (ﷺ) said: Ten are the acts according to fitra: clipping the moustache, letting the beard grow, using the tooth-stick, snuffing water in the nose, cutting the nails, washing the finger joints, plucking the hair under the armpits, shaving the pubes and cleaning one's private parts with water. The narrator said: I have forgotten the tenth, but it may have been rinsing the mouth. - Sahih:Muslim:261a (islam)

-is it obligatory, plucking hair from your armpit should be hurtful?
- Can you shave the armpit or do you have to pluck it out?
- What will happen if you don't do that?

Chapter: Seeking to beget children
Narrated Jabir:
I was with Allah's Messenger (ﷺ) in a Ghazwa, and when we returned, I wanted to hurry, while riding a slow camel. A rider came behind me. I looked back and saw that the rider was Allah's Messenger (ﷺ) . He said (to me), "What makes you in such a hurry?" I replied, "I am newly married." He said, "Did you marry a virgin or a matron?" I replied, "(Not a virgin but) a matron." He said, "Why didn't you marry a young girl with whom you could play and who could play with you?" Then when we approached (Medina) and were going to enter (it), the Prophet (ﷺ) said, "Wait till you enter (your homes) at night (in the first part of the night) so that the ladies with unkempt hair may comb their hair, and those whose husbands have been absent (for a long time) may shave their pubic hair." (The sub-narrator, Hashim said: A reliable narrator told me that the Prophet (ﷺ) added in this Hadith: "(Seek to beget) children! Children, O Jabir!") - Sahih:Al Bukhari:5245 (islam)

Chapter: Al-Qaza'
Narrated (Abdullah) bin `Umar:
Allah's Messenger (ﷺ) forbade Al-Qaza' (leaving a tuft of hair here and there after shaving one's head.) - Sahih:Al Bukhari:5921 (islam)

-Is it applicable today?
- What will happen to a Muslim who shave part of his head?
- Same question to a non-Muslim, Hell or Paradise?

Chapter: Reviving Dead Land
Narrated Zaynab:
She was picking lice from the head of the Messenger of Allah (ﷺ) while the wife of Uthman ibn Affan and the immigrant women were with him. They complained about their houses that they had been narrowed down to them and they were evicted from them. The Messenger of Allah (ﷺ) ordered that the houses of the Immigrants should be given to their wives. Thereafter Abdullah ibn Mas'ud died, and his wife inherited his house in Medina. - Sahih:Abu Dawud:3080 (islam)

-Was mohamed full of lice?
- Is it sunnah to have lice?

Chapter: What Has Been Related: When The Two Circumcised Organs Meet, Ghusl Is Required.
Aishah narrated:
"When the circumcised meets the circumcised, then indeed Ghusl is required. Myself and Allah's Messenger did that, so we performed Ghusl." - Sahih:Tirmidhi:108 (islam)

Chapter: The use of false hair
Narrated Ibn `Umar:
Allah's Messenger (ﷺ) said, "Allah has cursed such a lady as lengthens (her or someone else's) hair artificially or gets it lengthened, and also a lady who tattoos (herself or someone else) or gets herself tattooed. - Sahih:Al Bukhari:5937 (islam)

-Is it applicable today?
- can you artificially lengthens your hair?
- What about a toupee, is it Halal?