The closes thing to an explanation for this rhetorical device is to claim that it is indeed a sort of ancient word for a pun. Paronomasia that emphasizes the phonic similarities between two words. It can be very prevalent among wordplay, for both adults and children. Some examples are “meet” and “meat”, or “old lord”. It is a great device to use when one wants his words to be ambiguous. One can find this device in many epic poets as well as Shakespeare. They usually use it in the mouth of one of the villains, to mask his true intents.