Tekashi69 says the reason he almost came to blows with Slim 400 at ComplexCon all has to do with Benjamins he's making, and Slim isn't.

We got 6ix9ine Monday in L.A. where we asked what went down with Slim Sunday night at ComplexCon in Long Beach. TMZ got video of him being held back from attacking Slim, who was doing some major trash talking while blocking the door.

Tekashi has choice words for Slim, who he calls "dirty" and "broke" ... among other insults. 6ix9ine says they're beefing because only one of 'em is making bank, while the other's stuck in the hood. Ouch!

Sounds like Tekashi is aware of his precarious legal situation right now, telling us there's no way he was about to risk getting thrown in jail over a physical altercation.

His bodyguards are on the same page, BTW. Check out the clip.