According to some accounts, the mafia was able to slip a jar of poison pills to a cafe worker in the capital of Havana.
Some say the worker was meant to slip the poison into an ice cream cone, other say it was a milkshake. But at the crucial moment, the poison could not be dislodged from inside the freezer. It was frozen stuck.
Either way, this was the closest the CIA came to getting the marked man.
If anything could convince me there is a divine force it would be the number of times Castro avoided death through sheer luck. His existence is so statistically improbable that it can only be explained as having something watching over him.