The Quran

قالَ ادخُلوا في أُمَمٍ قَد خَلَت مِن قَبلِكُم مِنَ الجِنِّ وَالإِنسِ فِي النّارِ ۖ كُلَّما دَخَلَت أُمَّةٌ لَعَنَت أُختَها ۖ حَتّىٰ إِذَا ادّارَكوا فيها جَميعًا قالَت أُخراهُم لِأولاهُم رَبَّنا هٰؤُلاءِ أَضَلّونا فَآتِهِم عَذابًا ضِعفًا مِنَ النّارِ ۖ قالَ لِكُلٍّ ضِعفٌ وَلٰكِن لا تَعلَمونَ

Muhammad Asad

[And God] will say: "Join those hosts of invisible beings and humans who have gone before you into the fire!" [And] every time a host enters [the fire], it will curse its fellow-host - so much so that, when they all shall have passed into it, one after another, the last of them will speak [thus] of the first of them:¹ "O our Sustainer! It is they who have led us astray:. give, them, therefore, double suffering through fire!" He, will reply: "Every one of you deserves double suffering² - but you know it not."

The terms "first" and "last" refer here either to a sequence in time ("those who came earlier" and "those who came later") or in status ("leaders" and "followers"); and in both cases they relate, as the next sentence indicates, to the evil influence which the former exerted on the latter during their lifetime - either directly, as leaders of thought and persons of distinction, or indirectly, as forerunners in time, whose example was followed by later generations.
Lit., "to everyone a double [suffering]": i.e., for having gone astray and for having, by his example, led others astray. Cf. 16:25 - "on Resurrection Day they shall bear the full weight of their own burdens, as well as some of the burdens of those ignorant ones whom they have led astray".