Tafsir of Al-Haqqah 69:40

So I swear by whatsoever you see, and by whatsoever you see not, that this is verily the word of an honored Messenger. meaning, Muhammad. Allah gave this description to him, a description which carries the meaning of conveying, because the duty of a messenger is to convey from the sender. Therefore, Allah gave this description to the angelic Messenger in Surah At-Takwir, where he said,

إنه لقول رسول كريم ذى قوة عند ذى العرش مكين مطع ثم أمين

Verily, this is the Word of (this Qur'an brought by) a most honorable messenger. Owner of power (and high rank) with Allah, the Lord of the Throne. Obeyed and trustworthy. (81:19-21) And here, it refers to Jibril. Then Allah says,

وما صحبكم بمجنون

and your companion is not a madman. (81:22) meaning, Muhammad

ولقد رءاه باﻻفق المبين

And indeed he saw him in the clear horizon. (81:23) meaning, Muhammad saw Jibril in his true form in which Allah created him

وما هو على الغيب بضنين

And he is not Danin with the Unseen. (81:24) meaning, suspicious

وما هو بقول شيطن رجيم

And it (the Qur'an) is not he word of the outcast Shaytan. (81:25) This is similar to what is being said here

وما هو بقول شاعر قليﻼ ما تومنون