Dedan, Tema, and Buz were desert tribes in northern Arabia. The shaven temple people were mentioned in chapter 9 as people who lived in the desert of Arabia. Thus Jeremiah went to all the kings of Arabia as well as all the mixed people who lived in the desert among the various Arab tribes.
Next up on Jeremiah’s world tour was the land Uz, where Job lived. Exactly where Uz was seems difficult to ascertain. Uz was probably in Edom, south of Israel, in northern Arabia or southern Jordan. In Genesis, chapter 10, Uz was the first born son of Abram, whose father was Shem, who in turn had Noah as his father. Thus Uz was the great grandson of Noah. There also was a place in southern Syria with this name. Uz was the first born of Nahor and Milcah, the brother of Abraham in Genesis, chapter 22. Thus this country of Uz could have been named after any of these people so that it was a mixed people with some Israelites.