I’ll echo the question above with my own experience:
For eggs if from my own flock, I wouldn't rest them at all before incubating.
For shipped eggs, I would let them rest for around 24 hours—depending on when they arrive and how old they are. If it’s been a long trip or the eggs are a bit older, I get them into the incubator as soon as possible.
For locally purchased eggs, I assess how much they’ve been jostled during transport. If they seem relatively stable, I skip the rest period entirely.
People often randomly leave chicken eggs for me outside my gate (half breed fowl- like the 'my plymouth rock was humped by a red jungle fowl- lol).. I have a motion detector that alerts me when they drop them off. I assume they collect and deliver them in one go, so I don’t rest those either. So far, all the "gifted" (abandoned) eggs are developing just fine.