Genesis 36:37

And Samlah died, and Saul of Rehoboth by the river reigned in his stead.

Saul of Rehoboth by the river - rather, Rehoboth of the river; i:e., the Euphrates. The site of this place is supposed by Col. Chesney ('Euphrat. Exped,' 1:, p. 119) to be at Rahabeh, on the right bank, a little below the confluence of the Khabour. Bochart, Gesenius, and many others, fix on this town. There is another a few miles further down, on the opposite bank, called Rahabeh-Malik - i:e., 'royal,' to which Jewish writers assign the honour of being 'the city of Saul.' Whichever of these two places may be the Rehoboth of Saul, that king appears to have been a foreigner.