This idiom is used to introduce a special message from God. See how you translated it in [Jeremiah 1:4](../01/04.md). Alternate translation: "Yahweh gave me a message. He said, 'Do" or "Yahweh spoke this message to me: 'Do" (See: [[rc://en/ta/man/translate/figs-idiom]])
The word "mourning" can be translated with a verbal phrase. Alternate translation: "where people are mourning" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
Yahweh speaks of no longer acting towards the people with peace, steadfast love, and mercy as if these were items that he has taken away from them. Alternate translation: "I will no longer act towards them with peace ... or with steadfast love and mercy" (See: [[rc://en/ta/man/translate/figs-metaphor]])
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/translate/figs-123person]])