Al-Kāfi - Volume 1 > The issue that Allah’s holding people accountable remains unjustified without the Imam
Hadith #4

4ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ الْبَرْقِيِّ عَنْ خَلَفِ بْنِ حَمَّادٍ عَنْ أَبَانِ بْنِ تَغْلِبَ قَالَ قَالَ أَبُو عَبْدِ الله (عَلَيْهِ السَّلام) الْحُجَّةُ قَبْلَ الْخَلْقِ وَمَعَ الْخَلْقِ وَبَعْدَ الْخَلْقِ.

4. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from al-Barqi from Khalaf ibn Hammad from ’Aban ibn Taghlib from abu ‘Abdallah (a.s.) who has said the following. “A person with Divine authority is before the people, with the people and after the people.”