Psalms 136:19

Sihon king of the Amorites: for his mercy endureth for ever:

The psalm remembers the overthrow of Sihon, king of the Amorites, as one of the mighty deeds wrought for Israel. It ascribes that deliverance to a compassion that lasts forever. Those who had returned from exile sang this praise to declare that the same leading and protecting of Israel in former times had been shown to them as present mercy.