No, that's not what plagiarism means, and it's not just atheists who make that claim. Any serious student of religion will tell you the same thing, many of the stories in the Quran were taken from the Bible, and many of the stories in the Bible were taken from still older sources, God had nothing to do with revealing them to anyone, they're human inventions. So is god.
I know what 'plagiarism' means; so the disbeliever says: the Quran plagiarize the stories of the Torah or the Bible; while the believer says: no, both the stories of the Torah and the Quran were revealed by God.
I told another member, although of course you
out of your overpride, did not read it.
So I repeat it here:
God - be glorified - revealed many stories in the Torah, which suffered many alterations and much distortion; then God revealed the same and other stories in the correct form.
This is in the Quran about the stories written in the Torah or the Bible, and then were repeated in the Quran:
Quran 39: 23, which means:
{
God has revealed the best story b: a book [: the Quran] similar [to the story of the Torah c ], repeated d; at which e the skins of those who fear their Lord tremble with quivering f, then their skins and their hearts do soften to the admonition of God g.
Such [guidance] is God's guidance with which He guides whom He pleases.
But whomsoever God misguides, there will be none to guide him. h}
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b i.e. the best stories, which are the stories of the prophets that are mentioned in the Quran.
The indication of this is His saying – be glorified – in the
Quran 12: 3, which means:
(We do relate to you [Mohammed] the best of stories [of the ancient], by revealing this Quran to you.)
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c It means: The stories of the prophets that are mentioned in the Quran are similar to that mentioned in the Torah.
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d They were mentioned twice: one time in the Torah and the second time in the Quran.
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e i.e. at the story.
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f On account of what they heard of the stories of the past nations who denied the messengers

the apostles) and how God destroyed them with punishment.
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g On account of what they heard about the tales of those believing in the messengers and how God helped them against their enemies in the life of the World, and about the reward which God prepares for them in the Next Life.
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h This has also been explained in the interpretation of the Quran 16: 93
Which is also mentioned in the
Quran 15: 87, which means:
{
We have offered to you, [Mohammed], seven repeated a [stories which had been written in the Torah and have been repeated in the Quran], and the great Quran [in addition to that]. b}
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87
a Any words repeated in speaking or writing is called تثنية , like the Book of
Deuteronomy of the Bible, [which is called Deuteronomy] because
it was mentioned twice.
Therefore, (We have offered to you, [Mohammed],
seven [stories which had been written in the Torah and have been] repeated [in the Quran]) means: seven stories of the past prophets which we had mentioned to Moses, and his people had written them in the Torah, then when these stories have been written in the Quran, they have become ‘repeated’ stories: it means: they were written twice: the first time in the Torah for Moses, and the second in the Quran for Mohammed.
This is confirmed by His saying – be glorified – in the Quran 39: 23, which means:
(God has revealed the best story: a book [: the Quran] similar [to the story of the Torah], repeated, at which the skins of those who fear their Lord tremble with quivering, then their skins and their hearts do soften to the admonition of God.)
Therefore:
(God has revealed the best story) means : the best stories of the ancient people in order that your heart Mohammed may be reassured, and your nation may take lesson of the nations before them with their prophets.
The indication of this is His saying – be glorified – in the
Quran 12: 3, which means:
(
We do relate to you [Mohammed] the best of stories [of the ancient.])
(a book [: the Quran] similar [to the story of the Torah.])
It means: the stories that We have revealed in the Quran is similar to the stories of the prophets.
The indication of this is in His saying – be glorified – in the
Quran 87: 18-19, which means:
(
Surely, [We mentioned all] this in the former [heavenly] scriptures: The scriptures of Abraham and [the scriptures of] Moses [: the Torah.])
And in His saying – be glorified – in the
Quran 20: 133, which means:
(
Has not come to them the clear explanation of [the story of the past nations] that is in the former Scripture [: the Torah, the Psalms and the Gospel?])
(
repeated) means: it is mentioned twice: one time in the Torah and the other time it is for Mohammed in the Quran, so they became (repeated.)
(at which the skins of those who fear their Lord tremble with quivering)
It means: At such stories, the skins tremble with quivering.
The meaning: When believers hear the stories of the past nations who denied the messengers and how God terminated them with various kinds of punishment, then their skins quiver because of mentioning and hearing such stories, and they fear of their Lord and ward off His punishment by doing righteousness acts and avoiding the sins.
(then their skins and their hearts do soften to the admonition of God) because of the good reward and prosperity in Paradise, with which God promises them.
87
b It means: We have given you also the Quran, which none of the prophets had before, as to its fluency, eloquence, laws, telling about the past, foretelling about the future, and others.
As regards to
the seven stories mentioned in the Bible, the Book of Genesis, and are also mentioned in the Quran are:
the story of Adam, Noah, Abraham, Lot, Ishmael, Jacob and Joseph: all these came before Moses, and God mentioned their stories to Moses, so his people wrote them in the Torah Collection [and were then included in the Old Testament.]
The interpretation is by Mohammed-Ali Hassan Al-Hilly.
http://quran-ayat.com/interpretation.pdf
http://quran-ayat.com/pret/contents.php