why did Israel hands want Jim to go below deck to get a bottle of wine?

Israel Hands wants Jim to go below deck to get a bottle of wine, so he can arm himself with a knife. He plans to kill Jim.

He had risen from his position to his hands and knees, and though his leg obviously hurt him pretty sharply when he moved—for I could hear him stifle a groan—yet it was at a good, rattling rate that he trailed himself across the deck. In half a minute he had reached the port scuppers and picked, out of a coil of rope, a long knife, or rather a short dirk, discoloured to the hilt with blood. He looked upon it for a moment, thrusting forth his under jaw, tried the point upon his hand, and then, hastily concealing it in the bosom of his jacket, trundled back again into his old place against the bulwark.

This was all that I required to know. Israel could move about, he was now armed, and if he had been at so much trouble to get rid of me, it was plain that I was meant to be the victim.