Then will I cause you to dwell in this place, in the land that I gave to your fathers, for ever and ever.
Then will I cause you to dwell in this place - the apodosis to the "if ... if" (Jeremiah 7:5-6).
To dwell - to continue to dwell.
Forever and ever - joined with "to dwell," not with the words "gave to your fathers" (cf. Jeremiah 3:18; Deuteronomy 4:40).