Or HaChaim on Genesis 37:33/אור החיים על בראשית ל״ז:ל״ג

1 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.