Ezekiel 31:15

This is what the Lord God says: ‘On the day it was brought down to Sheol, I caused mourning. I covered the deep because of it; I held back its rivers; its abundant waters were restrained. I made Lebanon mourn for it, and all the trees of the field fainted because of it.
BSB · Berean Standard Bible
Thus saith the Lord God; In the day when he went down to the grave I caused a mourning: I covered the deep for him, and I restrained the floods 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.

Note to mourn: Heb. to be black

KJV · King James Version
“The Lord God says: ‘In the day when he went down to Sheol, I caused a mourning. I covered the deep for him, and I restrained its rivers. The great waters were stopped. I caused Lebanon to mourn for him, and all the trees of the field fainted for him.

Note Sheol is the place of the dead.

WEB · World English Bible
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.
ASV · American Standard Version

Related passages

From the Treasury of Scripture Knowledge, grouped by the word they explain.

I caused a
The deep and all the mighty rivers which cherished this fair tree are here described as mourning at his downfall: they stop their usual courses to bewail his fate, and Lebanon with all its stately trees, (his confederates and allies,) sympathise with him in his misfortunes.
Nahum 2:8–10; Revelation 18:9–11, 18, 19
mourn
Heb. be black.
Malachi 3:4