وَالسَّمَاءِ وَمَا بَنَاهَا وَالْأَرْضِ وَمَا طَحَاهَا وَنَفْسٍ وَمَا سَوَّاهَا
By the sky and the One who built it—or its building; the earth and the One who spread it—or its spreading; and a soul and the One who fashioned it—or its fashioning. (91:5–7)
With relative mā, the reference is to the One who built, spread or fashioned; with maṣdariyyah mā, it is to the building, spreading or fashioning. Both analyses are recognized in classical commentary.
The oath remains coherent under either analysis, though the syntactic object of the oath differs. Reading mā here automatically as a negation would misread the construction.