Tafsir of An-Nazi'at 79:27

(Is your creation more difficult) is an address to those addressed in the response to the oath—meaning those among the people of Mecca who deny resurrection—based on their claim of its difficulty. This is by way of rebuke and silencing, after He—Exalted is He—clarified the absolute ease of it in relation to the power of Allah Almighty by His saying: (But it will be only one shout).

"Creation" (khalqan) is in the accusative case as a specifier (tamyiz), and it is transformed from the subject (mubtada'); meaning: Is your creation after your death "more difficult"—that is, more arduous and harder—in your estimation, or "the heaven," meaning or the creation of the heaven, given its greatness and its encompassment of marvelous wonders, the least of which baffles the intellect to even perceive?

His saying—Exalted is He—(He built it) and what follows is an explanation and detailing of the manner of its creation, which is derived from His saying—Exalted is He—(or the heaven). In the omission of the mention of the subject in this [clause] and in the verbs that are conjoined to it, there is—as is not hidden—an indication of His designation and an exaltation of His majesty—Mighty and Majestic is He.