en_tn/jer/33/26.md

If I have not established ... and if I have not fixed ... then I will reject ... and not bring

This is a hypothetical situation that Yahweh never expects to be true. Alternate translation: "I have established ... and I have fixed ... so I will never reject ... and I will bring" (See: rc://en/ta/man/translate/figs-hypo)

I will restore their fortunes

"I will cause things to go well for them again" or "I will cause them to live well again" See how similar words are translated in Jeremiah 29:14.

show mercy to

Translate as "have compassion on" is translated in (Jeremiah 30:18).