Al-Kāfi

Hadith 731
wilayahwillrights
6ـ أَحْمَدُ بْنُ إِدْرِيسَ عَنْ مُحَمَّدِ بْنِ عَبْدِ الْجَبَّارِ عَنْ صَفْوَانَ بْنِ يَحْيَى عَنِ ابْنِ أَبِي عُثْمَانَ عَنِ الْمُعَلَّى بْنِ خُنَيْسٍ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلام) قَالَ إِنَّ الامَامَ يَعْرِفُ الامَامَ الَّذِي مِنْ بَعْدِهِ فَيُوصِي إِلَيْهِ.
6. Ahmad ibn Idris has narrated from Muhammad ibn ‘Abd al-Jabbar from Safwan ibn Yahya from (ibn) abu ‘Uthman from al-Mu‘alla ibn Khunays from abu ‘Abdallah (a.s.) who has said the following “The Imam (a.s.) knows the succeeding Imam and delivers his will to him.”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī