The Ruling on Wearing Shorts For Swimming or Otherwise

Question :

All praise belongs to Allâh. The following question was addressed to the General Chairman of the Permanent Committee for Scientific Researches and Religious Verdicts:

Many people, especially those groups associated with the army, wear sports clothes that leave uncovered a small area under the navel and half of the thighs, or more on some occasions.
This has become very widespread. Please give us your view on this important issue, and explain the Shari'ah ruling for it, important because it has become accepted among people to wear these clothes.

Answer:

Covering one's 'Awrah is obligatory according to a consensus of the Muslims. The woman's body is all 'Awrah, and there is a consensus that the buttocks and private parts of a man are his Awrah as well. But the correct scholarly opinion is that the Awrah for man is everything between his knee and navel. This is based on what is reported from "Ali, may Allâh be pleased with him, that the Prophet ﷺ said:
"Don't reveal your thigh, and don't look at somebody else's thigh, be they dead or alive."

It is reported that Muhammad bin Jahsh said that once, the Messenger of Allah uncovered. The Prophet ﷺ passed by Ma'mar, whose thighs were said:
"O Ma'mar, cover your thighs, for the thighs are 'Awrah."

Recorded by Ahmad in his Musnad, Al-Bukhari in disconnected form, and Al-Hakim in his Mustadrak

It is also reported from Ibn 'Abbas, may Allah be pleased with them, that the Prophet ﷺ said: "The thigh is 'Awrah."

Recorded by At-Tirmizi and Ahmad with the wording:
"Allah's Messenger ﷺ passed by a man whose thigh was exposed so he said:
"Cover your thigh, for a man's thigh is 'Awrah.".

It was also reported from Jarhad Al-Aslami that he said, "Allah's Messenger ﷺ passed by me while I was wearing a Burdah and my thigh was exposed. He said:
"Cover your thighs, for the thigh is 'Awrah."

Recorded by Malik in Al-Muwatta, Ahmad, Abu Dawud, and At-Tirmizi, who said it was Hasan. These Hadiths strengthen each other, so that they are raised to the level of being valid proofs.

Allah, send your prayers and blessings on Muhammad, on his family, and on his Companions.