Well, this is the first time I've figured out obfuscated code (so maybe it's not that obfuscated?!).
Spoiler follows: @q sets up anonymous arrays containing numbers which each represent a different letter. @w is an array for which each number represents a different word (there are lots of duplicate words in the phrase). Then the foreach loops iterate over each word, and then each letter is decoded by splitting a text string into an array. For instance, the first (0-indexed) item in the text string, t, corresponds to 0 in the @q array. A string is then built up for each word and then each word is added to an array with "push". Finally the result is output.