NOTES for Gen 30:25-43
It is not easy for a modern person to understand the system of livestock breeding and selection in ancient times. In short, Jacob uses techniques known to him so that his flock will have the color he needs. In this way he obtains a large herd and, therefore, wealth. To outsiders this prosperity becomes a sign of the special favor of Jacob's unknown God, for a reason they do not understand. It also becomes a stimulus for resentment, envy, and hatred. Gradually it becomes impossible to separate what arouses greater hostility: Jacob himself, his wealth, his skills, or his God.