put five on it

To place five American dollars on a dime ( small ) bag of marijuana. Usually used as a contribution towards the total sum of the marijuana.

Lupe did you contribute towards the weed? Why yes, I put five on it.

put this fo five in your throat

All put this fo five in your throat means is basically that some bitch is telling you to put a gun in ya mouth.

Kidnapper: “PUT THIS FO FIVE IN YOUR THROAT”
Innocent person: “why the fuck—?”