"Throw it on the pile" - where did this idiom come from?

("throw it in the pile" or "just throw it on the pile" are also acceptable variants)

I have seen this expression being used a lot. Based on context and intuition, I figured it has an idiomatic meaning, something like this. "It" refers something that should normally be significant, but this idiom is saying that we already have so many of things like "it" that "it" is no longer important. Here, "it" can refer to any kinds of thing, physical objects, facts, abstract concepts...

I tried searching around, but all I get is a whole bunch of different places that use the same expression. This affirms the fact that this is a common idiom, but make it hard to figure out the source.

I tried to search on the idiom dictionary but got nothing.

So does anyone know the source for this? Also, is my interpretation of the phrase correct? Thank you.

(I have also seen visual gags invoking this idiom as well: a character in movie or cartoon casually throw something valuable - like gold, or medal - into a big pile of similar stuff)

You can find plenty of examples by just searching for the phrase, but here is a random webpage just to make it concrete: https://bookmachine.org/2012/04/05/pottermore-sells-1-million-in-three-days-rowling-instructs-minions-just-throw-it-on-the-pile/

Solution 1:

In the days before digital working, office desks might have a pile (or tray) of incoming documents to be attended to. Similarly, in workplaces such (for example) repair workshops, there might be a pile of items awaiting repair. In both cases, new documents or items that arrived would be added to the pile. The worker might say to the person delivering a new item “Just put it on the pile”, implying that there are already many such items and that the new one is merely a small addition that must wait its turn.

By analogy, your interpretation is correct. The source of the saying lies long ago and, having its origin in the workplace as above, is probably unidentifiable.