en_tn/zec/10/12.md

I will strengthen them in myself

"I will cause them to be strong and to believe in me"

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 Zechariah 1:4. AT: "this is what Yahweh has declared" or "this is what I, Yahweh, have declared" (See: rc://en/ta/man/translate/figs-123person)