אַיֵּה֙ מְע֣וֹן אֲרָי֔וֹת וּמִרְעֶ֥ה ה֖וּא לַכְּפִרִ֑ים אֲשֶׁ֣ר הָלַךְ֩ אַרְיֵ֨ה לָבִ֥יא שָׁ֛ם גּ֥וּר אַרְיֵ֖ה וְאֵ֥ין מַחֲרִֽיד׃
Rashi on Nahum
Where is the lions’ den?—This is a lamentation over Nineveh, which was the dwellings of kings, hard and strong as lions.
Rashi on Nahum
where the grown lion and the old lion went—The place where the kings would go and leave their children there, like a lion that dwelt securely.