Genesis 37:33
And he knew it, and said, It is my son’s coat; an evil beast hath devoured him; Joseph is without doubt rent in pieces. And he knew it, and said, It is my son’s coat; an evil beast hath devoured him; Joseph is without doubt rent in pieces.
Jacob at once knew the blood-stained coat brought to him as his son Joseph's own garment. From that torn and bloodied evidence he concluded that an evil beast had devoured Joseph and rent him in pieces.
That conclusion was mistaken, for it rested on false evidence put before him by his sons. They deceived him with the coat and concealed from him the truth that they had sold Joseph, leaving him to believe Joseph was dead.
The imagined violent death brought Jacob intense grief that lasted a long time. For many days he refused comfort and mourned as one who would go down to the grave in sorrow for his son. He declared that he would mourn Joseph until his own death.
He continued to mourn Joseph as dead until they met again alive in Egypt. There Joseph left his chariot to run on foot to meet his father, and they embraced and wept over each other. Jacob's joy at seeing his son alive made him say he was now willing to die.
The verse belongs to the account of Joseph's suffering while virtuous, when he was maligned, persecuted, and treated as a criminal. Such suffering did not mean God had forsaken him, for God gave him signal victories despite appearances.