'Enemy' in the Bible

Saul was yet the more afraid of David; and Saul was David's enemy continually.

Saul said to Michal, "Why have you deceived me thus, and let my enemy go, so that he is escaped?" Michal answered Saul, "He said to me, 'Let me go! Why should I kill you?'"

The men of David said to him, "Behold, the day of which Yahweh said to you, 'Behold, I will deliver your enemy into your hand, and you shall do to him as it shall seem good to you.'" Then David arose, and cut off the skirt of Saul's robe secretly.

For if a man finds his enemy, will he let him go away unharmed? Therefore may Yahweh reward you good for that which you have done to me this day.

Then Abishai said to David, "God has delivered up your enemy into your hand this day. Now therefore please let me strike him with the spear to the earth at one stroke, and I will not strike him the second time."