Numbers 25:7-9

When Phinehas the son of Eleazar, the son of Aaron the priest, saw this, he left the congregation and took a spear in his hand, and he went after the man of Israel into the tent, and pierced both of them through the body, the man of Israel and the woman. Then the plague on the Israelites stopped. Nevertheless, those [Israelites] who died in the plague numbered 24,000.