He knew their desolate palaces; literally, widows; but the word is used figuratively in Isaiah 13:22, in the sense of "desolate houses" (comp. Isaiah 47:8). So the Vulgate gives didicit viduas facere; and Keil adopts that meaning here, "he knew, i.
e. outraged, the widows of Israel." The Revised Version admits it in the margin. The two words for "widows" and "palaces" differ in a single letter only, and there may have been an error in transcription.
On the whole, I adhere to the Authorized Version and Revised Version (text). Currey explains, "He knew (i.e. eyed with satisfaction) his palaces," from which he had ejected their former owners, as his father Jeboiakim had done (Jeremiah 22:15, Jeremiah 22:16).
Ewald follows the Targum in a various reading of the verb, and gets the meaning, "he destroyed its palaces." Interpreting the parable, we have Jehoiachin described as alarming Nebuchadnezzar and the neighbouring nations by his activity, and therefore carried off to Babylon as Jehoahaz lad been to Egypt.
The young lion was to roar in chains, not on the "mountains of Israel."