A paraphrase is a phrase used to express the meaning of something written with the use of different words. This is done in order for the writer to achieve more clarity while trying to express his message.
The phrases "get sunbeams out of cucumbers" and "trying to turn ice into gunpowder" are paraphrases used in order to give the message to the reader that the characters are trying to get the most out of the mentioned resources which are at their disposal.
