'Serving' in the Bible

When all the kings serving Hadadezer saw that they had been defeated by Israel, they made peace with Israel and served them. So the Arameans (Syrians) were afraid to help the Ammonites anymore.

But he was unwilling to listen to her. So he called out to a young man who was serving him, and told him: "Send this woman away from me and lock the door after her."

Besides, who else should I be serving? Why not the son? The same way I served your father, I'll serve you."