Is prayer while wearing shorts valid (short trousers)?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

The ‘Awrah of a man in prayer is from his navel to his knee. If this kind of trousers covers the space between the navel and the knee, then it is permissible to pray in it. Otherwise, it is impermissible. It is also a condition that these trousers are not transparent so that they reveal what is beneath them. It is forbidden to wear such things. The proof of this was narrated by Imaam Ahmad on the authority of Ibn ‘Abbaas, may Allaah Be Pleased with him, that the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said: "Cover your thigh. The thigh of a man is part of his ‘Awrah." [Saheeh] If they do not reveal what is beneath them but reveal its size, this is disliked according to the majority of scholars.

Allaah Knows best.