وَلَيَحْمِلُنَّ أَثْقَالَهُمْ وَأَثْقَالًا مَّعَ أَثْقَالِهِمْ ۖ وَلَيُسْـَٔلُنَّ يَوْمَ ٱلْقِيَـٰمَةِ عَمَّا كَانُوا۟ يَفْتَرُونَ Qur’an Al-Ankabut (29:13)Walaya h milunna athq a lahum waathq a lan maAAa athq a lihim walayusalunna yawma alqiy a mati AAamm a k a noo yaftaroon a
Cf. the Prophet's saying: "Whoever calls [others] unto the right way shall have a reward equal to the [combined] rewards of all who may follow him until Resurrection Day, without anything being lessened of their rewards; and whoever calls unto the way of error will have to bear a sin equal to the [combined] sins of all who may follow him until Resurrection Day, without anything being lessened of their sins" (Bukhari).
The burdens of those they misled.
Besides the burden of their own infidelity, they will bear the burden of deluding others with falsehood.