—“it is indeed the word conveyed by a noble messenger,”
that messenger being Gabriel—upon him be peace—
“one endowed with power, secure in the presence of the Lord of the Throne, obeyed there and trustworthy.”
In other words, he is obeyed in the heavens and worthy of trust.

Then Allah said:
“And your companion is not mad,”
meaning this companion whom Allah has bestowed upon you—He sent him as a messenger from your own kind to live among you, for you were unable to endure the sight of angels.
As the Most High also said:
“They say, ‘Why has an angel not been sent down to him?’ Yet had We sent down an angel, the matter would have been decided, and they would have been granted no respite. And had We appointed him an angel, We would surely have made him a man.”

The Exalted further said:
“Indeed, he saw him on the clear horizon,”
that is, he saw Gabriel, upon him be peace.

“And he is not suspected with regard to the unseen,”
that is, he is not accused of falsehood; in the other recitation, “nor is he stingy,” meaning he does not withhold knowledge or dispense it only for payment, as do those who conceal knowledge unless compensated.

“Nor is it the word of an accursed devil.”
Thus Allah declared Gabriel—upon him be peace—free of any kinship with devils, just as He cleared Muhammad, Allah bless him and grant him peace, of being a poet or a soothsayer.

[From the rational, scriptural proofs]
Therefore, the friends of Allah who model themselves on Muhammad—peace and blessings be upon him—act upon what he commanded, abstain from what he forbade, and follow his guidance in every matter he made clear. Allah supports them with His angels and with a spirit from Him; He casts lights from His radiance into their hearts, and they are granted the wondrous marks of honor with which Allah distinguishes them.