When Jacob took partially peeled, stripped, and spotted branches and placed them in the watering troughs so that they would be in front of flocks when they came to drink, did he believe that merely seeing the striped and spotted branches would cause the animals to give birth to spotted offspring? No, he did not. God commanded him [Genesis 31:9-12] to set up a striped branches, which he did, not as a physical means to the end of producing striped or spotted offspring, but rather as a symbol of Jacob’s faith and obedience.
Remember in a parallel situation God later caused Moses to set up a bronze snake in the wilderness when the people had been bitten by serpents. The people were not healed by the snake, they were healed by God through faith expressed in their obedience in looking to the snake. They were not looking to the snake for any power or healing, rather it was a symbol of what God was going to do.
In a parallel, but not identical way, Jacob’s trust in God would have been similarly rewarded. In the next chapter, Jacob speaks of having had a dream about streaked, speckled, and spotted cattle in which God spoke to him. It may be that God told him what to do on that occasion.
