John Calvin Commentary Genesis 30:37

"And Jacob took him rods of fresh poplar, and of the almond and of the plane-tree. And peeled white streaks in them, and made the white appear which was in the rods." — Genesis 30:37 (ASV)

And Jacob took him rods of green poplar. Moses's narrative, at first sight, may seem absurd: for he either intends to censure holy Jacob as guilty of fraud, or to praise his industry. But from the context it will appear that this skill was not blameworthy. Let us then see how it is to be excused.

Should anyone contend that he was driven to act as he did by the numerous injuries from his father-in-law, and that he sought nothing but compensation for former losses, the defense would perhaps be plausible: yet, in God's sight, it is neither sound nor likely; for although we may be unjustly treated, we must not respond with equal injustice.

And if it were permitted to avenge our own injuries, or to repair our own wrongs, there would be no place for legal judgments, and from that, horrible confusion would arise. Therefore, Jacob ought not to have resorted to this stratagem for the purpose of producing degenerate cattle, but rather to have followed the rule which the Lord delivers through Paul, that the faithful should study to overcome evil with good (Romans 12:21). This simplicity, I confess, Jacob ought to have cultivated, unless the Lord from heaven had commanded otherwise.

But in this narrative there is a hysteron proteron (a putting of the last first), for Moses first relates the fact, and then adds that Jacob had attempted nothing except by God's command. Therefore, those people who oppose malignant and fraudulent men with deceptions like their own cannot claim him as their advocate; because Jacob did not, of his own accord, take the liberty to craftily circumvent his father-in-law, by whom he had been unjustly deceived. Instead, pursuing the course prescribed for him by the Lord, he kept himself within proper limits.

Also, in my judgment, some dispute in vain from where Jacob learned this; whether by long practice or by the teaching of his fathers, for it is possible that he had been suddenly instructed about a matter previously unknown. If anyone objects to the absurdity of supposing that this act of deceit was suggested by God, the answer is easy: God is the author of no fraud when He stretches out His hand to protect His servant.

Nothing is more appropriate for Him, and more in accordance with His justice, than for Him to intervene as an avenger when any injury is inflicted. But it is not our place to prescribe to Him His method of acting. He allowed Laban to retain what he unjustly possessed; but in six years He withdrew His blessing from Laban and transferred it to His servant Jacob.

If an earthly judge condemns a thief to restore twofold or fourfold, no one complains; and why should we concede less to God than to a mortal and perishing man? He had other methods in His power, but He purposed to connect His grace with the labor and diligence of Jacob, so that He might openly repay to him those wages of which he had been long defrauded.

For Laban was forced to open his eyes. Previously, with his eyes shut, he had been accustomed to consume the sweat and even the blood of another person.

Moreover, concerning physical causes, it is well known that what the female sees greatly affects the form of the fetus. While this happens with women, it at least takes place with animals, in which there is no reason, but where an enormous rush of carnal lusts reigns.

Now Jacob did three things:

1. He stripped the bark from twigs to expose some white areas by making incisions in the bark, and thus a varied and multi-colored pattern was produced.
2. He chose the times when the males and females were gathered for mating.
3. He put the twigs in the watering troughs, because just as drinking nourishes the animal's body, it also stimulates the sexual drive.

By the stronger cattle, Moses may be understood as referring to those that bore young in spring—and by the feeble, those that bore young in autumn.