'Curse' in the Bible

they joined with their brothers, 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 do all the commandments of Yahweh our Lord, and his ordinances and his statutes;

because they didn't meet the children of Israel with bread and with water, but hired Balaam against them, to curse them: however our God turned the curse into a blessing.