en_tn/amo/02/16.md

flee naked

Possible meanings are 1) this is a metonym for "run away without his weapons" or 2) this is meant literally as "run away wearing no clothes" (See: rc://en/ta/man/jit/figs-metonymy)

in that day

"at that time"

this is Yahweh's declaration

Yahweh speaks of himself by name to express the certainty of what he is declaring. See how you translated this in Amos 2:11. Alternate translation: "this is what Yahweh has declared" or "this is what I, Yahweh, have declared" (See: rc://en/ta/man/jit/figs-123person)