1 Raja-raja 20:11

20:11 The king of Israel replied, “Tell him the one who puts on his battle gear should not boast like one who is taking it off.” ¹ 

[20:11]  ¹ sn The point of the saying is that someone who is still preparing for a battle should not boast as if he has already won the battle. A modern parallel would be, “Don’t count your chickens before they’re hatched.”