As a heifer of three years old - Which runs lowing from place to place in search of her calf, which is lost or taken from her.
The meaning is that, taking up the lamentation of Heshbon, the Moabites break forth into a wail, heard as far as Elealeh, scarcely two miles distant Numbers 32:37, but thence spreading over the land to towns on the southern and southwestern borders of the land.
An heifer of three years old - Applied in Isaiah 15:5 to Zoar, but here to Horonaim. Some take “an heifer” as a proper name, and render it: “Eglah for the third part” (compare Isaiah 19:24). Zoar, Horonaim, and Eglah formed a tripolis, or confederacy of three towns, and Eglah might therefore be put after either one or the other.
Nimrim - Probably the Wady-en-Nemeirah at the southeastern end of the Dead Sea.