The evidence that a man’s ‘awrah is from the navel to the knee

There are many ahadith which indicate that a man’s ‘awrah is the area between the navel and the knee (and the navel and knee are not part of the ‘awrah). See al-Majmoo’, 3/173; al-Mughni, 2/286 

These ahadith include the following: 

1 – Abu Dawood (3140) and Ibn Maajah (1460) narrated that ‘Ali (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings of Allah be upon him) said: “Do not show your thigh, and do not look at the thigh of anyone, living or dead.” 

2 – Ahmad (21989) narrated that Muhammad ibn Jahsh (may Allah be pleased with him) said: The Prophet (peace and blessings of Allah be upon him) passed by Ma’mar when I was with him, and his thighs were uncovered. He said: “O Ma’mar, cover your thighs, for the thigh is ‘awrah.” 

3 – Ahmad (15502), Abu Dawood (4014) and al-Tirmidhi (2798) narrated from Jawhad al-Aslami that the Prophet (peace and blessings of Allah be upon him) passed by him when his thigh was uncovered and he said: “Do you not know that the thigh is ‘awrah?” 

4 – al-Tirmidhi (2798) narrated from Ibn ‘Abbaas (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said: “The thigh is ‘awrah.” 

Shaykh al-Albaani said concerning these ahadith in al-Irwa’(1/297):  

Although their isnaads are not entirely free of weakness, they strengthen one another, because there is no narrator among them who may be regarded as suspicious, rather their weakness has to do with confusion and ambiguity. And there are similar reports which make one confident that the hadeeth is saheeh, especially since some of them were classed as saheeh by al-Haakim, and al-Dhahabi agreed with him. And al-Bukhaari narrated it in a mu’allaq report in his Saheeh… But a number of these isnaads give the hadeeth strength, and raise it to the level of being saheeh, especially since there are similar, corroborating reports on the same issue. End quote. 

It says in Fatawa al-Lajnah al-Daa’imah (6/165): 

Even though there is some weakness in the isnaads of these ahadith, as there are gaps in the chain of narrators or there is some weakness in some of the narrators, nevertheless they support one another, and when taken as a whole they provide the required evidence. End quote. 

The majority of fuqaha’ are of the view that these ahadith should be followed and they stated that a man’s ‘awrah is from the navel to the knee. See al-Mughni, 2/284 

And Allah knows best.