King Saul was a mad king for sure. He raised David as his own son with a fierce love that turned to jealousy, hatred, and murderous intentions. King David was a humble follower, turned leader. He was pursued to be murdered by his father figure and David never fought back or attempted to hurt Saul. He had opportunities to kill Saul, and save his own life, and always chose to give mercy.
Spears get thrown all the time - gossip, looks, rude comments to name a few of the spears - and we have 2 choices: pick the spear up and throw it back or dodge the spear and refuse to seek our own revenge.
Choosing to throw the spear in return might elevate you to leadership but it does so by turning you into the very leader that threw the spear at you in the first place. The only way to break that cycle and be a true leader is to lay the spear down.
Simplified: keep the mouth shut, keep the heart soft, keep the mind pure.