Nehemiah 10:28-30

Then the rest of the people—the priests, Levites, gatekeepers, singers, Temple servants, and all who had separated themselves from the pagan people of the land in order to obey the Law of God, together with their wives, sons, daughters, and all who were old enough to understand— joined their leaders and bound themselves with an oath. They swore a curse on themselves if they failed to obey the Law of God as issued by his servant Moses. They solemnly promised to carefully follow all the commands, regulations, and decrees of the LORD our Lord: “We promise not to let our daughters marry the pagan people of the land, and not to let our sons marry their daughters.