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
A Kush up is a very small hit of a joint. Experienced people in Kush ups can do multiple at a time. For instance 30 Kush ups = 30 continous small hits without blowing out the smoke, only at the end you are allowed to breathe again.
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.