'Second in command' in the Bible

Then he provided him with a chariot as his second-in-command, outfitted with a group of people who shouted out in front of him, "Bow your knees!" And that's how Pharaoh set Joseph over the entire land of Egypt.

Jonathan told him, "Don't be afraid. My father Saul won't find you, and you will be king over Israel. I'll be your second-in-command. My father Saul also knows this."