Musar על אסתר 4:2

The twelfth thing a man should remember is that the Holy One, Blessed be He, sees the thoughts of his heart. See how a man who goes to minister before the king adorns and beautifies himself, as it is written, "For you may not enter within the king's gate clothed with sackcloth" (Esther 4:2). And as we see in the story of Joseph, "Then Pharaoh sent and called Joseph, and they brought him hastily out of the dungeon. And he shaved himself, and changed his raiment, and came in unto Pharaoh" (Gen. 41:14). And behold and see that he who stands before the king always does not adorn himself (as lightly) as he who stands before the king for one moment. If this is so, then we who stand before the King of Kings forever — for He sees the thoughts of our hearts whether secret or revealed, and there is no escape from Him, for He is everywhere — should think always of His greatness and agree in our hearts to do His will and to adorn ourselves in our thoughts before Him.