Kill all the men who committed whoredom with Baalpeor.
Phinehas stops God's plague
6-8 When Aaron's grandson, Phinehas, saw an Israelite man and a Midianite woman having sex, he took his javelin and thrust it through man and the woman through her belly. And that stopped the plague. 9 But not before 24,000 Israelites had died.
For impaling the interracial couple, God rewards Phinehas with his "covenant of peace" (God's version of the Nobel Peace Prize) and his sons with the everlasting priesthood.