One way that a speaker can leave a lasting impression on listeners is to incorporate oral language that is artfully arranged and infused with rhythm. One device that helps a speaker accomplish this specific purpose is:

Usually repetition is used in oral cases to make emphasis in what the speaker is willing to communicate in his speech and also to make the oral speech more enjoyable with rhythm caused in words.

It refers to saying something twice but in different context.

Example:

"My conscience hath a thousand several tongues,

And every tongue brings in a several tale,

And every tale condemns me for a villain."

--Shakespeare, Richard III

im gonna take a guess and say gas vans and chambers