Genesis 30:37-43

³⁷Then Jacob took fresh rods of poplar, almond, and plane trees, and peeled white stripes in them, exposing the white that was in the rods. ³⁸He set the rods which he had peeled in front of the flocks in the drinking troughs, that is, in the watering channels where the flocks came to drink; and they mated when they came to drink. ³⁹So the flocks mated by the rods, and the flocks delivered striped, speckled, and spotted offspring. ⁴⁰Then Jacob separated the lambs, and made the flocks face toward the striped and all the black in the flock of Laban; and he put his own herds apart, and did not put them with Laban’s flock. ⁴¹Moreover, whenever the stronger of the flock were mating, Jacob would place the rods in the sight of the flock in the drinking troughs, so that they would mate by the rods; ⁴²but when the flock was sickly, he did not put them in; so the sickly were Laban’s, and the stronger were Jacob’s. ⁴³So the man became exceedingly prosperous, and had large flocks, and female and male servants, and camels and donkeys.