Answered by Shaykh Rami Nsour
Question:Before going into prayer does it make sense to have prayer clothes even though this sounds like Christian – “Sunday’s Best”?
Answer: It is recommended to wear one’s best clothes when praying alone, in congregation or on the Friday prayer. This recommendation can be achieved without setting aside a specific outfit for that prayer. But, if a person were to say set aside specific clothes for the Friday prayer, this would be a noble thing.
It is mentioned in the Rules of Burial (janaza) that if a person had a specific outfit for Friday prayers, that they should be buried in that, rather than just the simple shrouds of burial (kafan). This is because those are the clothes that the person would have done so much worship in and that would benefit them in the grave. [Mukhtasar Khalil]