These considerations yield certain knowledge that he was truthful in his declaration,
“Indeed, I am the Messenger of Allah to all of you” (Qur’an 7:158);
he was no liar and no fabricator. A claim of this magnitude can proceed only from the very finest and most complete of human beings—if it is true—or from the very worst and most corrupt—if it is false. The perfection of his knowledge and his religion, already described, is utterly incompatible with wickedness, malice, and ignorance. It is therefore inevitable that he possessed the highest degree of perfection in both knowledge and religion, which in turn necessitates that he was truthful in his proclamation, “Indeed, I am the Messenger of Allah to all of you” (7:158).

One who is not truthful must either lie deliberately or speak in error. The first would render him unjust and depraved; the second would render him ignorant and astray. Yet Muḥammad—peace and blessings be upon him—had a knowledge that rules out ignorance and a perfection of religion that rules out deliberate falsehood. Recognizing his qualities thus entails recognizing that he neither knowingly lied nor unknowingly uttered a lie. With both possibilities excluded, it follows necessarily that he was truthful and fully aware of his truthfulness.

For this reason Allah declared him free of both misguidance and willful wrongdoing:

“By the star when it descends!
Your companion has neither strayed nor erred;
Nor does he speak from his own desire.
It is but a revelation revealed.” (Qur’an 53:1–4)

Concerning the angel who brought the revelation, He said:

“Indeed, it is the word of a noble messenger,
possessed of strength, established in the presence of the Lord of the Throne,
obeyed there and trustworthy.” (Qur’an 81:19–21)

He then said about the Prophet:

“Your companion is not mad.
He saw him on the clear horizon.
He is not begrudging concerning the unseen.
And it is not the speech of an accursed devil.
So where are you going?
It is only a reminder for all peoples.” (Qur’an 81:22–27)

He also said:

“Truly, it is a revelation from the Lord of all worlds,
which the Trustworthy Spirit brought down upon your heart,
that you might be one of the warners,
in a clear Arabic tongue…” (Qur’an 26:192–195),
up to His words:

“Shall I inform you upon whom the devils descend?
They descend upon every sinful liar;
they listen in stealth, and most of them are liars.” (Qur’an 26:221–223)

The Exalted clarified that the devil descends only upon one suited to his purpose. Satan seeks evil—falsehood and licentiousness—and never seeks truth and justice; he therefore attaches himself only to someone in whom there is falsehood, whether deliberate or accidental, and wickedness as well. Indeed, error in religion itself is from Satan.

ʿAbdullāh ibn Masʿūd, when asked about a legal issue, said, “I shall answer it according to my opinion: if it is correct, it is from Allah; if it is mistaken, it is from me and from Satan, and Allah and His Messenger are clear of it.”

Thus the Messenger of Allah is absolved of the devils’ descent upon him, whether in deliberate falsehood or in error. By contrast, anyone other than a messenger might err, and his error is from Satan—even though he may be forgiven for it. Since no report transmitted by the Prophet can be shown to contain error, nor any of his commands to involve wrongdoing, it is known that the devil did not descend upon him; rather, a noble angel descended upon him.

For this reason Allah said elsewhere about the Prophet:

“Indeed, it is the word of a noble messenger;
not the word of a poet—how little you believe—
nor the word of a soothsayer—how little you take heed.
It is a revelation from the Lord of all worlds.” (Qur’an 69:40–43)

Here ends what he (may Allah have mercy on him) cited; it is exactly what he quoted word for word.