Question
I understand that during salaat, for men – the entire region from above the navel to below the knees, should not only be covered, but its shape should also be concealed, i.e., the clothing should not be skin-tight. Without this, the salaat is not valid. However, there are two issues I am worried about:
(a) The lower garment – I understand that the trousers should be loose and not tight-fitting or hugging closely the thighs and knees. But how loose is good enough? Is it considered sufficiently loose if there is enough free space in each leg of the trousers to fit an arm alongside the leg? This understanding of looseness becomes important when taken together with the below problem about the upper garment. I wish to understand if the validity of the salaat is affected by the situation.
(b) The upper garment – the kurta which covers till below the knee during standing position in salaat, rises up when in the ruku’ position. Although it still covers completely the posterior and most of the thighs, the problem is that the kurta rises up to about a few inches above the knee. During sajda, there is no problem as the back panel (daaman) of the kurta reaches the upper end of the ankles, and the thighs are folded inwards. However, during jalsah, again the kurta slightly rises – partially exposing the knees.
Answer
In fact, during Salaat and at all times when in public, the body should be covered appropriately from neck to above the ankles. This applies not only to Salaat. The notion that covering the aurah is sufficient, is baatil. While the validity of Salaat is reliant on covering the Satr/Aurah, it is sinful to perform Salaat with only the Satr covered if one has garments to cover the entire body.
If the trousers is so tight, e.g. jeans, which reveals the shape of the satr area, then it is as if he is naked. His Salaat is therefore not valid with such lewd kuffaar garb. The looseness should be such that the shape of the satr area is not at all visible.
A kurtah which rises a few inches above the knees during Ruku’ is not a proper kurtah. The kurtah should be midway between the knees and the ankles, then it will not rise above the knees during ruku’.
Furthermore, for practical purposes, ‘validity’ of Salaat should be understood in the context of Acceptance (Maqbooliyat) by Allah Ta’ala, not in the technical context appearing in the Kutub of Fiqh. Rasulullah (Sallallahu alayhi wasallam) said that Salaat performed haphazardly is struck into the face of the musalli as if it is an old dirty scrap cloth. This is regardless of the Fiqhi validity of the Salaat.
Therefore, Salaat performed with jeans, T-shirts, tight pants, even loose pants without a kurtah covering the satr area, garb with logos of any kind whatsoever, with elbows exposed, with western garb, and with pants below the ankles is NOT VALID. Such Salaat MUST be repeated with proper attire.

FROM THE MAJLIS VOLUME 26 NUMBER 02