Genesis 25:33-34; 28:20-22 NRSV
33 Jacob said, “Swear to me first.” So he swore to him, and sold his birthright to Jacob. 34Then Jacob gave Esau bread and lentil stew, and he ate and drank, and rose and went his way. Thus Esau despised his birthright.
20Then Jacob made a vow, saying, “If God will be with me, and will keep me in this way that I go, and will give me bread to eat and clothing to wear, 21so that I come again to my father’s house in peace, then the Lord shall be my God, 22 and this stone, which I have set up for a pillar, shall be God’s house; and of all that you give me I will surely give one tenth to you.”