Deuteronomy 17:14-17

When you enter the land that GOD, your God, is giving you and take it over and settle down, and then say, “I’m going to get me a king, a king like all the nations around me,” make sure you get yourself a king whom GOD, your God, chooses. Choose your king from among your kinsmen; don’t take a foreigner—only a kinsman. And make sure he doesn’t build up a war machine, amassing military horses and chariots. He must not send people to Egypt to get more horses, because GOD told you, “You’ll never go back there again!” And make sure he doesn’t build up a harem, collecting wives who will divert him from the straight and narrow. And make sure he doesn’t pile up a lot of silver and gold.