What is the origin of the "Oh my Jesus, save us from the fires of hell" prayer?

The Rosary prayer “oh my Jesus, save us from the fires of Hell, lead all souls to Heaven, especially those in most need of your mercy”
“fires of Hell”???
Fire is a gift from God to man-positive
Fire is used for cleansing/purging-positive
God is described by many theologians as being like a fiery furnace of love-positive
Is it possible that there is fire is Hell? I feel very doubtful.
And why is there a prayer in the Rosary that isn’t theologically sound?

That prayer was added to the prayers of the rosary because of the request of Our Lady of Fatima to Lúcia.

Our Lady of Fatima gave a vision of hell to the children:

Our Lady showed us a great sea of fire which seemed to be under the earth. Plunged in this fire were demons and souls in human form, like transparent burning embers, all blackened or burnished bronze, floating about in the conflagration, now raised into the air by the flames that issued from within themselves together with great clouds of smoke, now falling back on every side like sparks in a huge fire, without weight or equilibrium, and amid shrieks and groans of pain and despair, which horrified us and made us tremble with fear…

We then looked up at Our Lady, who said to us so kindly and so sadly:

You have seen hell where the souls of poor sinners go.

Jesus himself spoke of the hell as “where their worm does not die, and the fire is not quenched.” (Mark 9:48)

In the parable of the Rich Man and Lazarus the rich man is in a place that can only be described as hell when he says, “Father Abraham, have pity on me. Send Lazarus to dip the tip of his finger in water and cool my tongue, for I am suffering torment in these flames.” (Luke 16:24)

The Book of Revelation also describes the Devil, all fallen angels, and the people who followed them as being thrown into a “lake of fire.” (Rev 19:20; 20:10; 20:14-15; 21:8).

The use of fire imagery in the Scriptures is quite natural and reasonable. Fire can be used to either purify or burn. Fire can be used to cook, keep warm, provide light or it can be used to destroy.

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