Tafsir of Maryam 19:35

"It is not for Allah to take a son. Exalted is He!" (i.e., It is neither correct nor fitting for Him—Glorious is His majesty—to take such a thing. This is a refutation of the Christians and a declaration of His transcendence—Mighty and Majestic is He—above what they have fabricated against Him, Blessed and Exalted is He).

And His saying—Glorious and Exalted is He—"When He decrees a matter, He only says to it, 'Be,' and it is," is a rebuke by way of explaining that His affair, when He decrees any matter or brings it into existence, occurs in the swiftest of times. How could it be imagined that He would have a son—which is among the signs of need and deficiency—when such is His status?

Ibn Amir read "fa-yakūna" (فيكون) with the accusative case (nasb), as a response to the command (jawāb al-amr).