Not a lot.
And Jesus says more than anybody else.
In Matthew 5:22-31, Jesus is quoted several times as warning against it. He says nothing about being torched alive there forever in an indestructible body.
He warns against it again in Matthew 18:9 in what can only be described as a hyperbolic commentary on blaming parts of your body for your sins. He doesn't say anything about being tortured in hell forever.
He instructs us about whom we should fear in Matthew 10:28: "Do not be afraid of those who kill the body but cannot kill the soul. Rather, be afraid of the One who can destroy both soul and body in hell." I tend to take the word "destroy" literally. I picture it as meaning "obliteration" of "both soul and body." I do not see it in this context as literal for one and figurative for the other. I take this instruction to mean that we should have a healthy fear of God's power to judge, since He has the power to offer eternal life as His gift. But I see nothing here about being roasted alive for aeons.
Jesus decries the Pharisees' efforts to create converts to their legalism in Matthew 23:15 by saying the new converts become just as much sons of hell as their mentors. Not a politically correct observation. Also not a teaching about endless physical torment in flame. Nor does such a teaching surface a few verses later in 33 where He calls them the offspring of vipers and asks how they plan to escape hell.
The parallel passages to Matthew 5 in Mark 9:45-48 does apply a quote from Isaiah to describe hell: "their worm does not die, and the fire is not quenched." The original does indeed describe a prophetic vision of the consequences of God's judgment by Isaiah (66:24. But it only says that the worm does not die, and the fire is not quenched. It says nothing about the "bodies" in that scene being still filled with life. In fact, the impression is quite the opposite. Maybe the worm and the fire do not die out because they are being continually fueled with more bodies to consume.
Then, in that expansive picture of judgment Jesus paints in Matthew 25, Jesus clearly warns in verse 41:
Then he will say to those on his left, 'Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels.
Eternal fire. Prepared for the devil and his angels. But He does not say that those humans thrown there will endure it eternally.
Luke 12:5 echoes the instruction about whom to fear - given at the sending out of the twelve in Matthew 10 - as a polemic against the Pharisees, also given later after the twelve and 72 have returned and thousands are following Him. Still no elaboration about unending agony.
However, Luke 16:23 is part of the enigmatic story Jesus tells about Lazarus and the rich man. The rich man finds himself in hell (literally, the Greek word for "Hades," the place of the dead) and begs for Lazarus to bring just a dripping finger of water because he is "in agony in this flame." It's not a pretty picture. But no one says anything about it being eternal. Is the rich man's plea for his brothers motivated by the realization that he doesn't have much time left to beg (a terrible irony, since Lazarus lived and died a beggar at his gate) for their fate? Is the point of the story to relate actuality; to teach us something we needed to know about hell? Or to use the existing, probably Zoroastrian-Greek-originated beliefs about life and life after death to make a point:
"If they do not listen to Moses and the Prophets, they will not be convinced even if someone rises from the dead."
James, generally regarded as the Lord's brother, warns of the tongue's fiery destructive inspiration and capability (in what strikes me as a curious comparison to the Holy Spirit's fiery church-constructing activity in Acts 2) in his general epistle (3:6). Still nothing there about timeless excruciation.
Now, II Peter 2:4 does tell us something about hell: that it is a place of gloomy dungeons where God sent rebellious angels to be held for judgment. Angels. Not people. And not for eternity; just until judgment. Then Revelation 20:14-15 takes up the tale of what happens next:
Then death and Hades (the place of the dead) are thrown into the lake of fire, which is the second death. If anyone's name was not found written in the book of life, he was thrown into the lake of fire.
Revelation 21:8 gives us the final glimpse at the sinful and their fate: "their place will be in the fiery lake of burning sulfur. This is the second death."
I can't tell you how literally to take the Revelation to John. I don't believe anyone can. It is a highly symbolic book of apocalyptic vision. But I can tell you that nothing in those words says that anyone would survive being thrown into that lake of fire. Nothing. Not a hint. Not a reflection back to law or prophecy or Christ's words or His followers' teachings.
It is final. It is the "second death."
I am not a fan of stringing together tenuously-related scriptures to build a point. I do not have the clear and complete teachings of Biblical times on the question. I can tell you that "sheol" is the Hebrew word that comes closest to the concept of "hell" in the Old Testament, and it is sometimes translated "grave" or "pit." It is the final resting place of the body. I can tell you that, similarly, "hades" is the Greek word which simply describes the abode of the dead in literature as well as scripture. Sometimes its inhabitants are dead bodies; sometimes spirits.
I can tell you that when Paul is talking about "all" of us being changed in the twinkling of an eye into incorruptible flesh in I Corinthians 15:51-52, he is writing to Christians. To conclude that "we ... all" includes anyone other than those who put their hope in Christ is making an unwarranted and unsupported assumption. In fact, he distinguishes between the perishable and the imperishable - only one of which can inherit the kingdom of God. (Guess which one.)
So, in spite of disliking the occupation of building my point on all these somewhat-related scriptures, I don't have a lot more to go on and neither do you, unless God has been whispering to you on the sly. And the conclusion I come to is this:
We live. We die. We are all judged. (Whether we are raised at this point as spirits or in bodies as mortal as the ones we have now, I can't tell from scripture.)
Those whom God judges worthy are changed into incorruptible forms to live with Him forever on the new earth among the new heavens. Those whom God judges as unworthy just die. They perish. Whatever is left of them does not seem to be vivified, recycled, or tortured - but annihilated. Burned up in the lake of fire, the second death. Finally. Permanently. Irrevocably.
Fallen angels and demons, including Satan? I have no clearer picture of that. Perhaps, as beings created to be immortal, they do suffer immortally for the sin of having seen God and known His goodness yet opposing it forever. Perhaps, as beings created to be immortal yet becoming God's enemies, they are not worthy even of the immortality they might have enjoyed - and they too are extinguished.
And perhaps that lake of fire burns eternally, not because fuel is continuously added to it, but because God wills it as a reminder of the consequences of evil. But even that I would have to wonder about as a necessity for eternal survivors of an world turned evil, living endlessly in the companionship of God through His Son.
Nothing in scripture inarguably confirms or denies my view of eternity as a gift only for those given it by God.
Neither does it unquestionably paint a picture of human souls being physically tortured forever in a hell of fire as the expression of God's justice.
I have my reasons for holding the view I have; you have yours for your view. It is difficult for me to believe that God would mete infinite torture as punishment for finite sin; it is difficult for me to believe that He would even permit such a place to eternally exist. If Christ conquered sin and death, then He conquered it. Obliterated its power. If He did so on our behalf, then it makes no sense to me that its place should continue eternally. Perhaps "eternal" is meant literally. Perhaps it is meant figuratively. Still, I have to concede, it is described by Him as "eternal fire." And it surely has a purpose.
I believe in scripture. I believe in judgment. I believe that God is perfect in judgment. I believe in the kindness and severity of God. I believe in His mercy and His righteousness. I believe in what hymnist Elizabeth Clephane spoke of as the "trysting place where Heaven’s love and Heaven’s justice meet!":
I believe in the cross.