Matt. 13: 24 - 30 contains a parable spoken by the Lord Jesus himself. In it Jesus spoke of a symbolic sower who sowed symbolic seeds in a symbolic field. He also spoke of a symbolic enemy who came and oversowed them with symbolic weeds. The symbols culminate in a symbolic gathering of the weeds at the time of a symbolic harvest by symbolic reapers who burn them up.
Verse 36 records that the disciples came up to Jesus privately after and desired the interpretation of this parable. And from the next verse, Jesus answers as follows:
“The sower of the fine seed is the Son of man; the field is the world. As for the fine seed, these are the sons of the Kingdom, but the weeds are the sons of the wicked one, and the enemy who sowed them is the Devil. The harvest is a conclusion of a system of things, and the reapers are angels. Therefore, just as the weeds are collected and burned with fire, so it will be in the conclusion of the system of things. The Son of man will send his angels, and they will collect out from his Kingdom all things that cause stumbling and people who practice lawlessness, and they will pitch them into the fiery furnace." NWT
From Jesus' response we see him meticulously interpreting the key symbols in the parable. Sower as himself, field as the world, fine seed as the sons of the kingdom, weeds as the sons of the wicked one. etc. My particular focus is his interpretation of the burning of the the weeds with fire, which he interprets as "pitching all things that cause stumbling and people who practice lawlessness into fiery furnace." If all the interpretations have been literal up to this point, why do JW say fiery furnace is still a symbol?
To confirm the fiery furnace as a consistent literal interpretation that does not derive itself from the symbol of fire but is independently a real literal that could be symbolized without the use of fire, Jesus further spoke another parable in 49 - 50 with a totally different set of symbols that did not allude to fire at all. Yet when he would interpret the parable he refers to the fiery furnace again in the interpretation of the symbols relating to the throwing away of the unsuitable catch of a fishing dragnet.
Why would JWs still then claim that fiery furnace is a symbol and not a literal?