Jack be nimble,
Jack be quick,
Jack jump over
Jack be nimble! Even today this phrase expresses a suggestion to be quick and agile. The name Jack used to be only a nickname for John, but is now more and more frequently used as a stand-alone name.
The nursery rhyme Jack be Nimble refers to an English privateer (later pirate) named Black Jack Smatt. Black Jack lived on Jamaica, in Port Royal, which during the Golden Age of Piracy was known as “The Wickedest City on Earth”. Black Jack was one of the most famous pirates of the Caribbean, particularly for the reason of being notoriously clever (and quick and nimble) to escape from authorities, who in his later pirate years wanted to capture and hang him. Jack Smatt was portrayed in the Pirates of the Caribbean movies as Jack Sparrow, played by talented Johnny Depp.
Jumping over the candlestick was on old medieval game. It originated from an ancient pagan tradition of jumping over fires. A person was supposed to jump over a burning candle so that the flame was not extinguished. This was seen as a good luck forecast.