Something “in the offing” isn’t about to happen in the present, or even soon, but it will certainly happen before too long.
Offing is an early nautical term that describes the part of the ocean most distant from the shore but still visible.
So someone who is watching for a ship would first see it in the “offing” and realize that its arrival was imminent.
The phrase “in the offing” was first used during the sixteenth century and began as “offen” or “of-fin”.