Genesis 37:25-28 

As they sat down to eat their meal, they looked up and saw a caravan of Ishmaelites coming from Gilead. Their camels were loaded with spices, balm and myrrh, and they were on their way to take them down to Egypt. 26 Judah said to his brothers, “What will we gain if we kill our brother and cover up his blood? 27 Come, let’s sell him to the Ishmaelites and not lay our hands on him; after all, he is our brother, our own flesh and blood.” His brothers agreed. 28 So when the Midianite merchants came by, his brothers pulled Joseph up out of the cistern and sold him for twenty shekels of silver to the Ishmaelites, who took him to Egypt.