And Jacob did separate the lambs
The ringstraked, speckled, and spotted; and set the faces of the flocks,
that were all white, towards the ringstraked, and all the brown in the flock of Laban;
either to go before those that were all white, that they by looking at them might conceive and bring forth such, which was another artifice of Jacob's to increase his own sheep; or else he set at the water troughs the white sheep on one side of them, and on the opposite side the speckled ones that the same effect might also be produced the more successfully both by the rods and by the speckled lambs: and he put his own flocks by themselves, and put them not unto Laban's
partly that they might not be mixed together, but kept distinct, that what was his property might be discerned from Laban's; and partly, lest his spotted ones, being mixed with Laban's white sheep, by continual looking at them, should conceive and bring forth such likewise, and so his flocks be lessened.