"And let not those who disbelieve think that [our] extending [of life] for them is better for themself," up to the end of the verse. Muhammad said: The meaning of "extending [of life] for them" is that We prolong their lives and grant them respite. The phrase "that [Our] extending" (annama) is in the accusative case (nasb) due to the verb "think" (yahsabanna) taking it as its object.
﴿وَلا يَحْسَبَنَّ الَّذِينَ كَفَرُوا أَنَّمَا نملي لَهُم خير لأَنْفُسِهِمْ﴾ الْآيَة، قَالَ مُحَمَّد: معنى ﴿نُمْلِي لَهُم﴾ نطيل لَهُم ونمهلهم، وَنصب (أَنَّمَا) بِوُقُوع (يَحسبن) عَلَيْهَا.