What does Jeremiah 48:36 mean?

So my heart mourns for Moab like a flute playing a funeral song. My heart grieves for the people of Kir-heres, because everything they worked for is gone. Jeremiah 48:36 - Modern Text Bible

(God’s sorrow for Moab is deep and heartfelt, like the mournful sound of a flute at a funeral, because all their achievements have vanished.)