Here the metonym "eyes" represents what God sees. Possible meanings are 1) "doing what I consider evil" or 2) "doing evil knowing that I am watching" (See: [[rc://en/ta/man/jit/figs-metonymy]])
A person being young is a metaphor for the people of Israel first becoming a nation. Alternate translation: "from the time they were young" or "from the time that they became a nation" (See: [[rc://en/ta/man/jit/figs-metaphor]])
Possible meanings of this are 1) the word "hand" is a synecdoche for the person and the referent is the idols they had made. Alternate translation: "the idols they have made" Or 2) the phrase is a metonym for their evil practices. Alternate translation: "their evil practices" (See: [[rc://en/ta/man/jit/figs-synecdoche]] and [[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]])