Letting them rest for about 24 hours is good. Depending on the coffee a few days may develop additional flavors. Simpler coffees like Costa Rica a day/two is fine. More complex coffee like North Africa can gain a lot with a few more days.
Two things are happening. In the short term grinding and brewing coffee straight of of a roaster won’t allow the water to saturate the beans as well. While the water is trying to saturate the beans, gasses are simultaneously push the water out/away.
So no gas = no pushback.
In the longer timeframe, it’s a bit like the appeal of leftovers. Or aging scotch or cheese. Time works it’s magic to mellow/enhance. Take it too far! like a week* and you’re on the way to stale coffee, but less than that, a few days or so, and you’re good.
Store the beans in a jar or a zip baggy. Doesn’t have to be fancy. You’ll want to use it up inside of a week anyway. If you do go with a jar wash it out between batches. Coffee oils are oils, and oils go rancid.
BTW, if you aren’t seeing oils on the surface of the beans now, you may see them in a day or so.
Ever notice the beans clinging to the plastic walls of a grocery store beans hopper? That’s not a sign of quality. It’s a sign of nasty oil in a dirty bin.
* Caveat on this. There ARE times an espresso blend will get held back an absurdly long time. But espresso is to coffee as Quarks are to Newtonian Law. Espresso is a whole other magical beast.