Todd Bolen, in an article about the significance of Gehenna in the New Testament, claimed that it represents "the place of everlasting fiery torment." He suggested that the idea that Gehenna was a garbage dump with fires continually burning, has little or no archeological nor literary evidence to support it. The trash dump idea was attributed Rabbi David Kimchi in AD 1200.
Bolen quoted Jeremiah 7:31-32, where the prophet condemns the Jewish practice of burning their children in the fire as sacrifices to Moloch in the valley of Hinnom, and Isaiah 66:24, "their worm shall not die, their fire shall not be quenched," and stated:
It is not difficult to see, from these and other texts (e.g., 2 Kgs 23:10; 2 Chr 28:3, 33:6; Jer 32:35), why Jesus and his contemporaries used the word Gehenna ("valley of Hinnom") as synonymous with the place of everlasting fiery torment. Indeed, there is no reason to search further for ancient burning piles of discarded newspapers, product packaging, and junk mail.
But, I suggest that Mr. Bolen may have missed the significance of the words of Jeremiah, which he quoted, where God said of the burning of children as sacrifices to Molech or to Baal: "which I did not command, nor did it come into my mind."
In the New Testament, Jesus reveals God as a Father, and the church, the heavenly Jerusalem, is called "the mother of us all." [Galatians 4:26] According to Jeremiah, bringing children into the world, only to have them perish in a fire, has never come into God's mind. Christians who keep the commandments of God, and have the testimony of Jesus Christ, are the woman's seed, in Revelation 12:17.
In Jeremiah's prophecy, Gehenna is associated with the idea that God is a loving father, and the threat of burning up his own children in a fire never came into his mind.
That refreshing concept is no doubt the background associated with Gehenna, and the sense in which Jesus used the word. The fire that is not quenched is his word. Jesus was certainly not influenced by Jewish Targums, written centuries later, or even by the opinions of the Scribes and Pharisees of his own time, whose traditions, he said, transgressed the commandment of God. [Matthew 15:3, 6]
In the valley of Hinnom, the site where children were sacrificed was called Tophet, and it was defiled in one of the reforms of King Josiah.
2 Kings 23:10
And he defiled Topheth, which is in the valley of the children of Hinnom, that no man might make his son or his daughter to pass through the fire to Molech.
Perhaps this defiling included using the place as a garbage heap. The site was evidently a place of burials, evidently of people slain during the destruction of Jerusalem by Nebuchadnezzar.
Therefore, behold, the days come, saith the LORD, that it shall no more be called Tophet, nor the valley of the son of Hinnom, but the valley of slaughter: for they shall bury in Tophet, till there be no place.
Jeremiah referred to it as the "valley of the dead bodies." Eventually it is to be "holy unto the Lord," which suggests that there is hope even for those who are cast into Gehenna.
And the whole valley of the dead bodies, and of the ashes, and all the fields unto the brook of Kidron, unto the corner of the horse gate toward the east, shall be holy unto the LORD; it shall not be plucked up, nor thrown down any more for ever.