Albert Barnes Commentary Jeremiah 50:17

"Israel is a hunted sheep; the lions have driven him away: first, the king of Assyria devoured him; and now at last Nebuchadrezzar king of Babylon hath broken his bones." — Jeremiah 50:17 (ASV)

Israel is a scattered sheep – that is, is like a flock which has been scared and driven in all directions, for lions have chased him.

First the king ... – Rather, the first lion “ate him, namely the king of Assyria; and this one, the last, has picked his bones, namely Nebuchadrezzar etc.” The constant wasting of the land by the Assyrians had so lessened the number of Israel, that Nebuchadnezzar had only the bones to pick.