إِنَّآ أَنزَلْنَا عَلَيْكَ ٱلْكِتَٰبَ لِلنَّاسِ بِٱلْحَقِّ فَمَنِ ٱهْتَدَىٰ فَلِنَفْسِهِۦ وَمَن ضَلَّ فَإِنَّمَا يَضِلُّ عَلَيْهَا وَمَآ أَنتَ عَلَيْهِم بِوَكِيلٍ
"We sent the Book down to you, for people, with the truth. Whoever finds the way, it is to his own good; whoever strays, strays to his own harm. You are not a guardian over them."
وَمَآ أَنتَ عَلَيْهِم بِوَكِيل — wakīl: root و-ك-ل, one who takes a matter upon himself and carries it through, one who bears the responsibility.
The limit is drawn plainly here, and it settles into a ruling the question of the nineteenth verse (a-fa-anta tunqidhu man fi'n-nār). The same limit was treated in al-Aḥqāf at 46/35 (balāgh) and in Qāf at 50/45 (wa mā anta ʿalayhim bi-jabbār). Three sūras say the same thing with three different words: delivery, not being a compeller, not being a guardian.