en_tn/isa/50/03.md

I clothe the sky with darkness; I cover it with sackcloth

These two phrases mean basically the same thing. Yahweh speaks of causing the sky to become dark as if he were clothing it with sackcloth. Alternate translation: "I make the sky dark, as if it were wearing dark sackcloth" (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/figs-parallelism)