Genesis 25:32-34

Names of God Bible

³² “I’m about to die.” Esau said. “What good is my inheritance to me?”

³³ “First, swear an oath,” Jacob said. So Esau swore an oath to him and sold him his rights as firstborn. ³⁴ Then Jacob gave Esau a meal of bread and lentils. He ate and drank, and then he got up and left.

This is how Esau showed his contempt for his rights as firstborn.