Prayer in a very light garment without long trousers

Q: A questioner from Yemen says: Some people pray in a very light garment without long trousers. Is their prayer valid? And what do you advise them?

A: If the one praying is a man, it is obligatory for him to cover the area between the navel and the knee. If the garment is light and the aforementioned awrah (part of the body that must be covered) is visible through it, the prayer is not valid. However, if the clothing covers the thighs and the rest of the awrah, and his flesh is not visible through it, there is no blame on him. Or if he is wearing sufficient trousers that cover the area between the navel and the knee, it does not harm him that the garment is light. Nevertheless, it is prescribed for the man to cover his shoulders or one of them. Based on his saying (peace and blessings be upon him): It is agreed upon that it is authentic.
As for the woman, she must cover her entire body in prayer, and her clothing must be covering and thick such that nothing of her body is visible through it, except only the face in prayer. If she exposes her hands, there is nothing wrong with it, but it is better to cover them. It is not permissible for her to pray in light garments through which her flesh is visible and its color is known, whether red or black. If a non-mahram (a relative one may not marry) sees her, she must also cover her face.