Charles Ellicott Commentary Ezekiel 31:16

"I made the nations to shake at the sound of his fall, when I cast him down to Sheol with them that descend into the pit; and all the trees of Eden, the choice and best of Lebanon, all that drink water, were comforted in the nether parts of the earth." — Ezekiel 31:16 (ASV)

Hell, in this context, is, as is generally understood, Sheol or Hades, the world of the departed.

Shall be comforted: Compare to Isaiah 14:9-10, which was probably in Ezekiel’s mind.