Q: How to tranfer ipod touch imessages to iphone 5 or mac

Hi guys

So I've had my ipod touch for a few years now, however, I'm giving it away and I have a lot of imessages on there that I would like to keep.

Over the years I also got a Macbook Air and iPhone 5.

My iphone imessages have transfered over to my itouch and my mac but my itouch messages are only on my ipod and doesn't show up on any other device.

How would I be able to transfer those imessages to one of the other devices?

Thanks!