Rashi on Genesis
ויאמר כתנת בני AND HE SAID, MY SON’S COAT —is this (i.e. supply the words היא זו after בני).
Or HaChaim on Genesis
טרוף טורף יוסף, "Joseph has been torn to shreds!" Jacob meant that Joseph had endured a twofold tearing (this is why Jacob said טרף twice). 1) A wild beast had torn him and killed him. 2) That animal had dragged him to its lair; as a result of this even a search for his remains was futile and he, Jacob, could not even bury his body. Were it not for this interpretation why did Jacob not organise a search for Joseph's remains? The brothers were clever enough to stress: "this we have found, examine please, etc." They made it plain to Jacob that they had not even found any bones.
Tur HaArokh
חיה רעה אכלתהו, “a wild beast has devoured him.” He did not say that robbers had slain him, for if so they would have robbed him of his precious tunic.