Narrated by ‘Ali (R.A): The Messenger of Allah (pbuh) said: “Do not show your thigh, and do not look at the thigh of anyone, living or dead.”(Abu Dawood (3140) and Ibn Maajah:1460) The majority of fuqaha’ are of the view that these ahaadeeth should be followed and they stated that a man’s ‘awrah is from the navel to the knee. See al-Mughni, 2/284 Most of the scholars say it is authentic and a man should cover navel to knee.
Silk is haraam for males, because the Prophet (pbuh) said: “These two [gold and silk] are forbidden for the males of my ummah and permissible for the females.” Narrated by Ibn Maajah, 3640; classed as saheeh by al-Albaani in Saheeh Ibn Maajah.
The scholars are agreed that it is haraam for men to to wear pure silk, because of the hadeeth of ‘Ali ibn Abi Taalib (R.A), who said that the Prophet (pbuh) took a piece of silk in his right hand and a piece of gold in his left, held them aloft and said: “These are haraam for the males of my ummah and permitted for the females.” (Reported by Ibn Maajah, 2/1189).
Abu Moosa (R.A) reported that the Prophet (pbuh) said: “Gold and silk have been permitted for the females of my ummah and forbidden for the males.” Indeed, a stern warning has been narrated concerning this matter, as was reported by al-Bukhaari (5853) and Muslim (2069) in the hadeeth of Ibn ‘Umar (R.A), who reported that the Prophet (pbuh) said: “Silk is only worn in this world by the one who will have no share of the pleasure of the Hereafter.” Anas (R.A) reported that the Prophet (pbuh) said: “Whoever wears silk in this world will not wear it in the Hereafter.” (Reported by al-Bukhaari, 5832).
The scholars allowed men to wear silk in certain exceptional circumstances where there is shar’i evidence to support this, such as Muslim combatants in war who are allowed to wear silk in order to show off and annoy the enemy, which is a kind of psychological warfare. People who are sick may also be permitted to wear silk to relieve their suffering, as Anas (R.A) reported that the Prophet (pbuh) allowed ‘Abd al-Rahmaan ibn ‘Awf(R.A) and Ibn al-Zubayr ((R.A) to wear silk because of a skin irritation that they suffered from. (Reported by al-Bukhaari, 10/295, and Muslim, 3/1646).
The scholars also allowed men to wear garments containing four fingers’ width of silk, because of the hadeeth of ‘Umar ibn al-Khattaab (R.A) who said that the Prophet (pbuh) forbade the wearing of silk except for an area the width of two fingers, or three or four.” (Reported by Muslim, 3/1644).
If the item that a man is going to wear is made of natural silk, then it is not permissible for him to wear it, no matter how it looks or feels, and no matter whether it is a shirt, pants, socks, a necktie or anything else.
Similarly it is not permissible to wear the skin of a dead animal (one that has died of natural causes) unless it has been tanned. With regard to wearing clothes made of wool, goat hair and camel hair, these are pure and permissible.
It is not permissible to wear thin or see-through clothing that does not conceal the ‘awrah and it is haraam to imitate the mushrikeen and kuffaar in their manner of dress, so it is not permissible to wear clothing that is unique to the kuffaar.
Narrated by ‘Abd-Allaah ibn ‘Amr ibn al-‘Aas (R.A) said: The Prophet (pbuh) saw ‘Ali (R.A) wearing two garments dyed with safflower and said: “These are garments of the kuffaar; do not wear them.”(Muslim, 2077)
It is haraam for women to imitate men and men to imitate women in the way they dress, because the Prophet (pbuh ) cursed the men who imitate women and the women who imitate men.” (Narrated by al-Bukhaari, 5546).
It is Sunnah to pay attention to keeping one’s clothes clean, without feeling arrogant or exaggerating about that.
Narrated by ‘Abd-Allaah ibn Mas’ood (R.A): The Messenger of Allah (pbuh) said: “No one will enter Paradise in whose heart is a mustard-seed of arrogance.” A man said: “What if a man likes his clothes to look nice and his shoes to look nice?” He said: “Allaah is Beautiful and loves beauty; arrogance means rejecting the truth and looking down on people.”(Narrated by Muslim, 91).
It is mustahabb to wear white clothes because the Prophet (pbuh) said: “Wear white clothes, for they are the best of your clothes, and shroud your dead in them.” Narrated by al-Tirmidhi, 994, hasan saheeh. This is what the scholars regarded as mustahabb. Also narrated by Abu Dawood, 4061; Ibn Maajah, 1472.
It is haraam for the Muslim man to let any garment he wears hang down beneath his ankles (an action known as isbaal); the limit for any garment is the ankles.
Narrated by Abu Hurayrah (R.A) that the Prophet (pbuh) said; “Whatever of the lower garment is beneath the ankles is in the Fire.”(al-Bukhaari, 5450. )
Narrated by Abu Dharr (R.A) that the Prophet (pbuh) said: “There are three to whom Allah will not speak on the Day of Resurrection and will not look at them or praise them, and theirs will be a painful torment.” the Prophet (pbuh) repeated it three times. Abu Dharr (R.A) said: “May they be doomed and lost; who are they, O Messenger of Allaah?” He said: “The one who lets his garment hang beneath his ankles, the one who reminds others of favours he has done, and the one who sells his product by means of false oaths.” (Muslim,106)
In Islam It is haraam to wear garments of fame and vanity, which means a garment that stands out from others so that people will look at the wearer and he will become known for it.
Narrated by Ibn ‘Umar (R.A): The Prophet (pbuh) said: “Whoever wears a garment of fame and vanity, Allaah will dress him in a garment like it on the Day of Resurrection.” According to another version, “…then set it ablaze.” And according to a third version, “will dress him in a garment of humiliation.” Narrated by Abu Dawood, 4029; Ibn Maajah, 3606 and 3607; classed as hasan by Shaykh al-Albaani in Saheeh al-Targheeb, 2089.
And Allah knows best.