Then they took Joseph’s robe and slaughtered a goat and dipped the robe in the blood.
31. And they took Joseph’s coat. They now return to their first scheme. In order that their father may have no suspicion of their crime, they send the bloody coat, from which he might conjecture that Joseph had been torn by some wild beast.
I. Joseph would soon be missed, great enquiry would be made for him, and therefore his brethren have a further design, to make the world believe that Joseph was torn in pieces by a wild beast; and this they did, 1. To clear themselves, that they might not be suspected to have done him any mischief. Note, We have all learned of Adam to cover our transgression, Job 31:33.
Commenting on Genesis 37:31-36
And they sent the coat of many colours,.... Which was what they dipped in the blood of the kid; this they sent to Jacob in such a condition, by the hand of some messenger; the Targum of Jonathan says, the sons of Zilpah and Bilhah; but more probably some of their servants, whom they instructed what to say to their father when they presented it...