Jacob owned a long-bladed knife which he used for many of his tasks on the Island, including weaving his tapestry and filleting fish for his breakfast. The knife was left in the cabin after it had been abandoned. Ilana found it in the wall of the cabin pinning up a fragment of the bottom-left corner of Jacob's tapestry on which a picture of the statue of Taweret had been woven. ("The Incident, Part 1")