I have seen few places you mentioned that salaah will be makrooh, like performing behind an Imam who shaves or clips his beard or jummah salaah is makrooh where khutba is in English. What exactly does Makrooh Salaat mean? Does it mean there is no problem or is it a sin of some kind?
Wa Alaikum Assalaam,
Makrooh means an act which is disliked/reprehensible. When the Imam/leader does an action which is reprehensible in Islam and is in opposition to the instruction of the Prophet (S.A.S), then he is considered to be sinful in that regard. For example, shaving/trimming the beard shorter than a fist length is going against the teaching of the Prophet (S.A.S). This instruction is not one which is deemed to be light, but it has been given the ruling of being Wajib by all the Imams of Fiqh. When the Imam leads a Salaah in this condition, then he is leading it in the state where he has violated a clear-cut, essential injunction given by the Prophet (S.A.S) and hence, considered as sinful.
For this reason, the Salaah which he leads is not in its best manner due to his condition. Though, it will be valid and accepted, it will still be affected on account of his state. Therefore, Makrooh salaah means that the salaah is not in its 100% best form due to the presence of something which is against the teachings of Islam. However, it will still be valid and accepted. It will not be a sinful Salaah.
And Allah knows Best.
Mufti Waseeem Khan.
This answer was collected from DarulUloomTT.net, which is operated under the supervision of Mufti Waseem Khan from Darul Uloom Trinidad and Tobago.