Jeremiah 48:45,46

They that fled stood under the shadow of Heshbon, &c. They that fled for fear of the enemies' forces thought to find shelter and safety in Heshbon, a strong fenced city. Or, instead of, because of the force, the Hebrew מכח, may be rendered for want of force, or strength, namely, force of their own to withstand the enemy. But a fire shall come forth out of Heshbon, and a flame from the midst of Sihon That is, of the city of Sihon, meaning still Heshbon. When the enemies have possessed themselves of Heshbon, they will quickly spread like fire over the rest of the country. Thus the prophet fitly applies to the present case the words of an ancient poem made upon Sihon's conquests over Moab, and recited by Moses, Numbers 21:27, where see the notes. And shall devour the corner of Moab, and the crown of the head of the tumultuous ones By the corner may be meant the borders, or extreme parts of the country. So the Hebrew word פאת signifies, Numbers 34:3; Nehemiah 9:22. The nobility, who are the stay and support of the government, are expressed by the crown of the head. By the tumultuous are meant those that are proud and haughty in their state and plenty, and insult over their inferiors. Wo be unto thee, O Moab! This verse is likewise taken out of Numbers 21:19. The people of Chemosh perisheth People are sometimes denominated from the God they worship: so the Jews were called the people of the Lord, or Jehovah.