In the Qur'an we find the following two statements:
If Allah had willed to choose a son,
He could have chosen what He would of that which He hath created.
Be He Glorified! He is Allah, the One, the Absolute. (Pickthall)
Sura 39:4 and 6:101 agree on the actuality, that Allah does not have a son, but they contradict each other in the issue of ability or possibility.
Sura 39:4 clearly states that God could have taken Himself a son from among his creation, i.e. without the necessity of a consort to father such a son. But Sura 6:101 clearly rejects the same idea as a logical impossibility.
Contradictions in the Qur'an
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