Nehemiah 10:29-31

29They clave to their brethren, their nobles, and entered into a curse, and into an oath, to walk in God’s law, which was given by Moses the servant of God, and to observe and to do all the commandments of the LORD our Lord, and his judgments and his statutes;

30and that we would not give our daughters unto the peoples of the land, nor take their daughters for our sons:

31and if the peoples of the land bring ware or any victuals on the sabbath day to sell, that we would not buy of them on the sabbath, or on a holy day: and that we would forgo the seventh year, and the exaction of every debt.