Answered by Shaykh Faraz Rabbani
1) Is it makrooh tahrimi or tanzeehi to pray in a garment which exposes your forearm i.e. t-shirt? I have heard some Indo/Pak people say it is makrooh.
2) Is it also makrooh not to cover the head and wear long shorts which cover your knees but expose your shins?
Walaikum assalam,
It is either somewhat disliked (makruh tanzihan) or better not to pray in a garment which exposes your forearm. It is not sinful, though, so while one should not do it, it is not something to ‘make a big deal of’ with others.
It is somewhat disliked to pray with one’s head uncovered or dressed in clothes not worn in front of respectable (religious) people. [Ibn Abidin] An example mentioned by fuqaha is praying in one’s pajamas.
This too, though, is not sinful, so one should only advise people against it if one thinks that the advice will be of benefit.
Also, it is only the act that is disliked. It remains obligatory to pray, even in this state.
Wassalam,
Faraz Rabbani.