Per kalyso's definition, this refers to a high grade brand of marijuana made famous by the reggae song. However, the artist for that song is Frankie Paul, not Shabba Ranks.
"Pass the kushungpeng, pass it over"
A common name for marijuana in Reggae music.
I don't smoke cigarette 'cause it puts out my breath.
I don't sniff coke 'cause it would make I choke.
All I smoke is the reefer shungpeng.
Kushungpeng make I wanna smoke again.
Pass the Kushungpeng, pass it over.
So if you use the cannabis let me hear you shout
Hip Hip Hooray! Hip Hip Hooray!
~Kushungpeng, Shabba Ranks