Numbers 25:6-8, 14-15

Just then one of the Israelite men brought a Midianite woman into his tent, right before the eyes of Moses and all the people, as everyone was weeping at the entrance of the Tabernacle. When Phinehas son of Eleazar and grandson of Aaron the priest saw this, he jumped up and left the assembly. He took a spear and rushed after the man into his tent. Phinehas thrust the spear all the way through the man’s body and into the woman’s stomach. So the plague against the Israelites was stopped

The Israelite man killed with the Midianite woman was named Zimri son of Salu, the leader of a family from the tribe of Simeon. The woman’s name was Cozbi; she was the daughter of Zur, the leader of a Midianite clan.