Dressing to Kill at Services

Section 699 [As a mark of humility], Rava used to remove his [costly] upper cloak, clasp his hands, and pray, explaining what he did: [I pray] like a slave in the presence of his master.

So much for getting dressed up for services. What a lovely idea. We don't try to show off for G!d, we act contrite and like G!d's slaves.