'Enemy' in the Bible

Thy right hand, O Jehovah, is glorious in power, Thy right hand, O Jehovah, dasheth in pieces the enemy.

The enemy said, I will pursue, I will overtake, I will divide the spoil; My desire shall be satisfied upon them; I will draw my sword, my hand shall destroy them.

If thou meet thine enemy's ox or his ass going astray, thou shalt surely bring it back to him again.

But if thou shalt indeed hearken unto his voice, and do all that I speak; then I will be an enemy unto thine enemies, and an adversary unto thine adversaries.