Indeed, Hova’s first big feature was Mary on “Can’t Knock the Hustle”. That came about because she used to date Dame Dash. Former entertainment lawyer and current media personality Combat Jack shared the full story with his readers

Jay also plays on joint and Mary J, which links back to the previous line about moving drugs during droughts: hustlers often fell back on weed when other drugs' supplies were running out.

The first part of this verse is recorded in the slowed-down “Chopped and Screwed” style popularized by Houston’s DJ Screw. The sound of the voice is meant to mimic the effects of purple drank

Swisher Sweets cigars, commonly used for blunt-rolling and beloved of Southern rappers:

“Slab” is Houston speak for an old-school car outfitted with rims, candy paint, etc.

“Sixes” refer to the rims, which in this case are 26 inches.

A tip of the hat here to another bunch of iconic Southern rap personalities, Memphis' legendary Three 6 Mafia

Could be referring to purple drank or weed. For all the purple drank shout-outs in his discography, Rocky has actually never been to Houston. From an interview with Complex Magazine:

I’m just really influenced by Houston’s culture. That’s the shit that really gets me going. Houston all the way. I never been there but I just love the culture. I’m quite sure Wu-Tang had never been to China before, but they were influenced [by Chinese culture] and you couldn’t tell them that they weren’t

[The Houston sound] is so attractive. It’s melodic, so it attracted me. I’m influenced by purple drink. I don’t give a fuck. I’ll sip it, so what? I think we all should sip it. Modern-day hipster shit. When it comes to Houston, I’m really attracted to the culture. Swanging, tipping, leaning, all that. That shit is dope

This lyric is a play on the ‘run’ and ‘walk’ aspects. People with prestigious allure (such as most MMG artists) are in such demand that some places pay a lower end fee for something as simple as an appearance.

Wale ought to be careful about where he’s “blowing down” – his native D.C. leads the country in per capita pot busts, and over 90% of the people arrested are black