The Arabs
is most likely a reference to the peoples living in the desert south and east of Jerusalem (much of it was/is wilderness). We had earlier met Geshem the Arab in Nehemiah 2:19. The Ammonites
lived east of Jerusalem on the yonder side of the Jordan River, extending into the distant desert (Numbers 21:21–24). The Ashdodites
were the inhabitants of Ashdod, a city of the Philistines to the west. The Persians tagged the entire district of the Philistines as Ashdod.
Together with the reference to Sanballat and Tobiah
who lived in Samaria (north), this verse tells us of (hostile) parties on Jerusalem’s every side: north, south, east, and west.
7 But when Sanballat and Tobiah and the Arabs and the Ammonites and the Ashdodites heard that the repairing of the walls of Jerusalem was going forward and that the breaches were beginning to be closed, they were very angry.