"You a whole cokehead out here, bruh," Jackson says.
"Asking you for advice about weed is like asking somebody who went broke on how to stay rich. You a whole cokehead out here, bruh!!"
Jackson later apologized for the comments ... saying he didn't mean to disrespect the ex-Yankee who's tried to turn around his life after being suspended 3 times for cocaine during his baseball career.
But, Stephen didn't back off his initial opinion at all ... doubling down and saying, "If you think weed is a gateway drug, then you weak-minded."
Jackson added, "It's a gateway for weak-minded people. That's just what it is. So if you weak-minded, don't smoke weed because it's going to make you try coke and crack."