"Jacob" and "Israel" are the two names of the ancestor of the Israelites, and these names are metonyms for the Israelites. Alternate translation: "descendants of Jacob ... you Israelite people" (See: [[rc://en/ta/man/jit/figs-metonymy]])
Yahweh speaks of himself by name to express the certainty of what he is declaring. See how you translated this in [Jeremiah 1:8](../01/08.md). Alternate translation: "this is what Yahweh has declared" or "this is what I, Yahweh, have declared" (See: [[rc://en/ta/man/jit/figs-123person]])
The abstract noun "captivity" can be translated using the noun "captive." Alternate translation: "from the place where they were captives" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])
Jacob's name is a metonym for his descendants. Yahweh speaks to Jacob as if he were speaking to another person. You may need to make explicit to where Jacob will return. Alternate translation: "Jacob will return to his own land ... he will be secure" or "The descendants of Jacob will return ... they will be secure" or "You descendants of Jacob will return ... you will be secure" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-explicit]])