Al-Kāfi
Hadith 730 5ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ مُحَمَّدِ بْنِ الْحُسَيْنِ عَنِ ابْنِ مَحْبُوبٍ عَنِ الْعَلاءِ بْنِ رَزِينٍ عَنْ عَبْدِ الله بْنِ أَبِي يَعْفُورٍ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلام) قَالَ لا يَمُوتُ الامَامُ حَتَّى يَعْلَمَ مَنْ يَكُونُ مِنْ بَعْدِهِ فَيُوصِيَ إِلَيْهِ.
5. Muhammad b. Yahya has narrated from Muhammad b. al-Husayn from Ibn Mahbub from al-‘Ala’ b. Razin from ‘Abdallah b. Abi Ya‘fur from Abi ‘Abdillah (a.s.) who has said the following: “The Imam does not die until he learns who the succeeding Imam is so he would deliver his will to him.”