King Ahab, whilst under pressure by a foreign king, responds to verbal threats with this telling proverb:
Ahab answered, "Tell him: One who puts on his armour should not boast like one who takes it off." 2kings 20v11
In effect Ahab is saying "a sober assessment when readying for battle is prudent; you haven't beaten me yet, you've yet to do battle & return home safely".
A welcome proverb for us when people write us off; or when our own self confidence allows us to get ahead of ourselves...