Genesis 25:33
“Swear to me first,” Jacob said.
What it says
Jacob insists on an oath, and Esau swears and sells him the birthright.
What it is doing
This verse makes the exchange formal and final.
In context
29One day, while Jacob was cooking some stew, Esau came in from the field and was famished. 30He said to Jacob, “Let me eat some of that red stew, for I am famished.” (That is why he was also called Edom.) 31“First sell me your birthright,” Jacob replied. 32“Look,” said Esau, “I am about to die, so what good is a birthright to me?” 33“Swear to me first,” Jacob said. 34So Esau swore to Jacob and sold him the birthright. Then Jacob gave some bread and lentil stew to Esau, who ate and drank and then got up and went away. Thus Esau despised his birthright.