Tesettur - The coverage of private parts

These days, i see a lot of muslims neglecting the coverage of most area from knees to navel. My request is that could you please state some hadiths or suras concerning the men's "tesettur" as well as the detailed information as when and how (e.g. do we need to hide our knees too, or they are excluded).. I could really use that to warn my friends. Thank you very much for your time.

Dear Brother / Sister,

The body parts of a man, which must be covered, are from the navel to the lower end of the kneecap. Majority of scholar are unanimous that the kneecap is from the thighbone and must be covered too. The evidences to this are the hadiths of the Prophet Muhammad (PBUH) given below;

“The private parts (body parts which must be covered) of a man is between the navel end the kneecap.” (Ahmad b. Hambel, II, 187). “Kneecap is included to the private parts.” (Zaylai, Nasbu’r-Raye, I, 297).

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