There’s a word used in the Bible to describe God’s anger against us being appeased: propitiation. “To understand [propitiation], think about how a mother and father become angry when a child sins. How does the child persuade his parents to cease to be angry and become happy with him? In our home, our children have to sit in a timeout, then tell us what they did wrong, and finally ask for forgiveness. Then we give big hugs and kisses. That’s propitiation. It means turning away anger. In the Bible, propitiation is an act by which God’s wrath is turned away from us.” – Daniel Hyde, “Jesus Christ: Our True Mercy Seat.”

In this passage, God’s wrath against sin was appeased through the killing of an animal. This is a pointer to Jesus who is the “propitiation for our sins” (1 John 2:2)