Albert Barnes Commentary Ezekiel 31:15-17

"Thus saith the Lord Jehovah: In the day when he went down to Sheol I caused a mourning: I covered the deep for him, and I restrained the rivers thereof; and the great waters were stayed; and I caused Lebanon to mourn for him, and all the trees of the field fainted for him. 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. They also went down into Sheol with him unto them that are slain by the sword; yea, they that were his arm, [that] dwelt under his shadow in the midst of the nations." — Ezekiel 31:15-17 (ASV)

Effect of Assyria’s fall.

I covered the deep - To cover with sackcloth was an expression of mourning (Ezekiel 27:31). The deep, the source of Assyria’s prosperity (Ezekiel 31:4), was made to mourn, being dried up instead of yielding its waters, its glad abundance (Ezekiel 31:15).

For him - On his account.

Floods ... great waters - Or, rivers ... the multitude of waters .

Lebanon represents the country that Assyria governed; “the trees,” the tributary princes (Ezekiel 31:16).

See the marginal references (Ezekiel 31:16).

His arm ... - The subject princes who were his strength and support in war (Ezekiel 31:17).