Why is there more sympathy and less harsher language used for Moab than in other prophecies of Isaiah?
This may be because Moab tended to be less violent than other nations of that time and because there was a connection between Israel and Moab. The Moabites were descendants of Lot (Genesis 19:30–38), and in Deuteronomy 2:9, the Israelites are told not to engage in battle over land with the Moabites. In addition, Ruth, who later became the great-grandmother of David, was also a Moabite (Ruth 1–4).
9 Aussi je pleure sur la vigne de Sibma, comme sur Jaezer; Je vous arrose de mes larmes, Hesbon, Elealé! Car sur votre récolte et sur votre moisson Est venu fondre un cri de guerre.