Quran verse 6:125 contains a phrase about Allah constricting a man’s chest as though he were climbing into the sky. This verse is interpreted on Muslim websites as proof that Allah, not Mohammed, wrote the Quran, because Mohammed could not have known that the air is thin at the top of a mountain.
Actually, the Arabic verb used is yaṣṣaʿʿadu, which, according to the Quran Arabic corpus dictionary, means climbing or running uphill.
Thus the meaning of the phrase is that climbing a tall sand dune makes you out of breath, which Mohammed (who had led caravans before becoming a prophet) would have known.
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