The words "silver and gold" are a metonym for the treasures that the nations would bring into the temple ([Haggai 2:7](./06.md)). (See: [[rc://en/ta/man/translate/figs-metonymy]])
Yahweh speaks of himself by name to express the certainty of what he is declaring. See how you translated this in [Haggai 1:9](../01/07.md). AT: "this is what Yahweh has declared" or "this is what I, Yahweh, have declared" (See: [[rc://en/ta/man/translate/figs-123person]])