The Lord is quite demanding on the appearance of his congregational leaders in the OT. He talks about dignity and the Lord’s glory in matters related to apparel in Exodus 28-30.. He also deals with presumption and an overly familiar approach to worship in the example of Nadab and Abihu.
And JUST as 'demanding' in the NT as well...
James 2:2
Suppose a man comes into your meeting wearing a gold ring and fine clothes, and a poor man in filthy old clothes also comes in