"And they shall surely bear their burdens," meaning the sins of their own selves. "And burdens along with their burdens," meaning they shall bear some of the sins of those whom they led astray, and that shall not decrease anything from the sins of those who followed them.
Yahya reported from Khalid, from al-Hasan, from Abu Hurayrah, who said: The Messenger of Allah, peace be upon him, said: "Whoever calls to guidance and is followed in it, he shall have the like of the reward of those who followed him, without that diminishing any of their rewards. And whoever calls to misguidance and is followed in it, he shall have the like of the burdens of those who followed him, without that diminishing any of their burdens."
Surah al-Qasas (from verse 14 to verse 18).
﴿وليحملن أثقالهم﴾ يَعْنِي: آثَامَ أَنْفُسِهِمْ ﴿وَأَثْقَالا مَعَ أثقالهم﴾ يَقُولُ: يَحْمِلُونَ مِنْ ذُنُوبِ مَنِ اتَّبَعَهُمْ عَلَى الضَّلَالَةِ، وَلَا يَنْقُصُ ذَلِكَ مِنْ ذُنُوبِ الَّذِينَ اتَّبَعُوهُمْ شَيْئًا.
يَحْيَى: عَنْ خَالِدٍ، عَنِ الْحَسَنِ، عَنْ أَبِي هُرَيْرَةَ قَالَ: قَالَ رَسُولُ اللَّهِ عليه السلام: " أَيُّمَا دَاعٍ دَعَا إِلَى هُدًى فَاتُّبِعَ عَلَيْهِ، كَانَ لَهُ مِثْلُ أَجْرِ مَنِ اتَّبَعَهُ مِنْ غَيْرِ أَنْ يَنْقُصَ مِنْ أُجُورِهِمْ شَيْءٌ، وَأَيُّمَا دَاعٍ دَعَا إِلَى ضَلالَةٍ فَاتُّبِعَ عَلَيْهَا، كَانَ لَهُ مِثْلُ أَوْزَارِ مَنِ اتَّبَعَهُ مِنْ غَيْرِ أَنْ يَنْقُصَ مِنْ أَوْزَارِهِمْ شَيْءٌ ".
سُورَة الْقَصَص من (آيَة ١٤ آيَة ١٨).