Oaths used for Pledging Allegiance to Sovereigns
Source: TTT
2 Kings 11:4
Then in the seventh year, Jehoiada sent for the commanders of hundreds, the Carites, and the guards, and had them brought into the house of the LORD. There he made a covenant with them and put them under oath. He showed them the king’s son
Ecclesiastes 8:2
Keep the king’s command, I say, because of your oath before God.