John Calvin Commentary Genesis 37:31

"And they took Joseph`s coat, and killed a he-goat, and dipped the coat in the blood;" — Genesis 37:31 (ASV)

And they took Joseph’s coat. They now return to their first scheme. So that their father might not suspect their crime, they send the bloody coat, from which he might conjecture that Joseph had been torn by some wild beast. Although Moses alludes to this briefly, yet I think that they rather sent some of their servants, who were not accessory to the crime, than any of themselves.

For soon afterwards, he says that his sons and daughters came to offer some consolation to him in his grief. And although an appearance of insult lurks in the words they use, it seems more probable to me that they gave this command to avert suspicion from themselves. For they feign a confused mind, as is usual in perplexing situations.

Yet whatever they intend, their wickedness drives them to the point that they inflict a deadly wound on their father's mind. This is the profit hypocrites gain from their disguises: in wishing to escape the consequences of one fault, they add sin to sin. As for Jacob, it is a wonder that after he had been tried in so many ways, and always emerged a conqueror, he should now sink under grief.

Certainly, it was very absurd that his son's death should cause him greater sorrow than the incestuous pollution of his wife, the slaughter of the Shechemites, and the defilement of his daughter. Where was that invincible strength by which he had even prevailed over the angel? Where the many lessons of patience with which God had exercised him, so that he might never fail?

This disposition to mourn teaches us that no one is endowed with such heroic virtues as to be exempt from that infirmity of the flesh, which betrays itself sometimes even in little things. Thus it also happens that those who have long been accustomed to the cross, and who, like veteran soldiers, ought bravely to bear up against every kind of attack, fall like young recruits in some slight skirmish. Who then among us would not fear for himself, when we see holy Jacob faint after having given so many proofs of patience?