Ezekiel 31:15 Thus says the Lord Yahweh: In the day when he went down to Sheol I caused a mourning: I covered the deep for him, and I restrained the rivers of it; and the great waters were stayed; and I caused Lebanon to mourn for him, and all the trees of the field fainted for him.
Ezekiel 31:16 I made the nations to shake at the sound of his fall, when I cast him down to Sheol with those who descend into the pit; and all the trees of Eden, the choice and best of Lebanon, all that drink water, were comforted in the lower parts of the earth.
Ezekiel 31:17 They also went down into Sheol with him to those who are slain by the sword; yes, those who were his arm, that lived under his shadow in the midst of the nations. — World English version
In this above verses Yahweh is speaking of Pharaoh of Egypt. (Ezekiel 31:2) Some commentators say that Yahweh is speaking of the king of Assyria. (Ezekiel 31:3) Sheol occurs three times in these verses. The King James Version twice renders it as “hell”, here and once as “grave”. The JFB Commentary tells us that his being cast into sheol is equivalent to, “I cast him into oblivion” (compare Isaiah 14:9-11)*. There is nothing here that gives us any thought that the ones being spoken of in sheol were being tortured.
*Fausset, A. R., A.M. “Commentary on Ezekiel 31“. “Commentary Critical and Explanatory on the Whole Bible”. 1874.