Here "they" still refers to the people of Israel. You can continue stating this is second person. Alternate translation: "if you escape" (See: [[rc://en/ta/man/jit/figs-123person]])
Egypt and Memphis refer to the people who live there. Alternate translation: "the army of Egypt will capture you. You will die there, and the people in the city of Memphis will bury you" (See: [[rc://en/ta/man/jit/figs-metonymy]])
Briers growing in the places where Israelites stored their silver is spoken of as if the briers were human enemies that would take the Israelite's precious possessions for themselves. Alternate translation: "Sharp briers will grow where they store their precious things of silver" (See: [[rc://en/ta/man/jit/figs-metaphor]])
Here "sharp briers" and "thorns" mean the same thing. To have briers and thorns growing represents a land that has become desolate and like a wilderness. (See: [[rc://en/ta/man/jit/figs-doublet]] and [[rc://en/ta/man/jit/figs-metonymy]])