Joshua 6:17-19

The city and all that is in it are to be devoted to the LORD. Only Rahab the prostitute and all who are with her in her house shall be spared, because she hid the spies we sent. But keep away from the devoted things, so that you will not bring about your own destruction by taking any of them. Otherwise you will make the camp of Israel liable to destruction and bring trouble on it. All the silver and gold and the articles of bronze and iron are sacred to the LORD and must go into his treasury.”