It is not the word of a poet.... This is the Revelation sent down from the Lord of the Worlds.

So I swear by whatsoever you see, (38) And by whatsoever you see not, (39) That this is verily the word of an honoured Messenger [i.e. Jibril (Gabriel) or Muhammad SAW which he has brought from Allâh]. (40) It is not the word of a poet, little is that you believe! (41) Nor is it the word of a soothsayer (or a foreteller), little is that you remember! (42) This is the Revelation sent down from the Lord of the Worlds (mankind, jinn and all that exists). (43)

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Quran: Chapter Al-Haaqqa (69), Verses 38-43