Hit That Jive, Jack!

"Hit that joint and pocket it, I've gotta run and go see my (implied) dealer"

Yup, that's basically it. There's no need to clutch your pearls, weed themed jazz and blues was a big thing back then. google "jazz and weed" if you need receipts

So the story goes like this maybe; There's two guys, both wearing fedoras and pin stripe suits I think, one guy's get up is more worn out and dusty than the other guy, who has a golden pocket watch. The guy with the pocket watch is about to go down town to buy some marijuana pot, but before he leaves, he gives his pipe to the dusty looking turkey. He says, hey man, hit this, it's pretty much all I have for now so take one hit (hit that jive, Jack)...oh yeah, the dusty guy's name is Jack I guess. Then he's like, "just hit the pipe once but then put it in your pocket till I get back. This will ensure that we will have some marijuana drugs for later, because even though I'm going downtown to pick up some more smoking pot, you never know what could happen, it could be a big wild goose chase, you never know. Cause that's where I'm going. Down town to buy more marijuana." So then, he's like "I'm going down town to see a "man" (that's hip lingo for his illegal narcotics and drug dealer) but since you're hitting that pipe right now, you're gonna have to finish taking that hit, and then put the light down and wait till the bowl cools- nah, forget it I don't have time to shake your hand right now, see ya sometime after, I don't know how long I'll be, bye for now Jack" and then he leaves to meet his marijuana reefer joint pot dealer downtown. So the whole thing basically is about this guy going downtown to buy drugs and leaving his friend uptown cause his dealer spooks easy and everyone back then had a machine gun, so like, he can't be bringing new people around all the time. His dealer probably also wears a good fedora.