Each Imam knows the succeeding Imam 
The words of Allah, the Most High, “Allah commands you to deliver the trust to its people,”(4:58) is a reference to the Imams
7 Aḥadīth
Al-Husayn ibn Muhammad has narrated from Mu‘alla ibn Muhammad from al-Hassan ibn Ali al-Washsha’ from Ahmad ibn ‘A’idh from ibn ’Udhayna from Burayd al-‘Ijli who has said that I asked abu Ja‘far about the following verse of the Holy Quran. “Allah (God) commands you to return that which had been entrusted to you to the rightful owners. Be just when passing judgment among people. . .” (4:58) The Imam said, “ We are intended thereby. The preceding Imam must transfer to the succeeding Imam the books, the knowledge and the armaments. ‘Be just when passing judgment among people’ means what is in your possession. Then Allah has said to people, “Believers, obey God, His Messenger, and your leaders (who possess Divine authority). . .” (4:59) This is how it was revealed. How Allah, the Most Holy, the Most High, would command them to obey the people who possess authority and then allow people to dispute them? This is said to those who are commanded by the command of, “Believers, obey God, His Messenger, and your leaders (who possess Divine authority). . .” (4:59)
الْحُسَيْنُ بْنُ مُحَمَّدٍ عَنْ مُعَلَّى بْنِ مُحَمَّدٍ عَنِ الْحَسَنِ بْنِ عَلِيٍّ الْوَشَّاءِ عَنْ أَحْمَدَ بْنِ عَائِذٍ عَنِ ابْنِ أُذَيْنَةَ عَنْ بُرَيْدٍ الْعِجْلِيِّ قَالَ سَأَلْتُ أَبَا جَعْفَرٍ عَنْ قَوْلِ الله عَزَّ وَجَلَّ إِنَّ الله يَأْمُرُكُمْ أَنْ تُؤَدُّوا الاماناتِ إِلى أَهْلِها وَإِذا حَكَمْتُمْ بَيْنَ النَّاسِ أَنْ تَحْكُمُوا بِالْعَدْلِ قَالَ إِيَّانَا عَنَى أَنْ يُؤَدِّيَ الاوَّلُ إِلَى الامَامِ الَّذِي بَعْدَهُ الْكُتُبَ وَالْعِلْمَ وَالسِّلاحَ وَإِذا حَكَمْتُمْ بَيْنَ النَّاسِ أَنْ تَحْكُمُوا بِالْعَدْلِ الَّذِي فِي أَيْدِيكُمْ ثُمَّ قَالَ لِلنَّاسِ يا أَيُّهَا الَّذِينَ آمَنُوا أَطِيعُوا الله وَأَطِيعُوا الرَّسُولَ وَأُولِي الامْرِ مِنْكُمْ إِيَّانَا عَنَى خَاصَّةً أَمَرَ جَمِيعَ الْمُؤْمِنِينَ إِلَى يَوْمِ الْقِيَامَةِ بِطَاعَتِنَا فَإِنْ خِفْتُمْ تَنَازُعاً فِي أَمْرٍ فَرُدُّوهُ إِلَى الله وَإِلَى الرَّسُولِ وَإِلَى أُولِي الامْرِ مِنْكُمْ كَذَا نَزَلَتْ وَكَيْفَ يَأْمُرُهُمُ الله عَزَّ وَجَلَّ بِطَاعَةِ وُلاةِ الامْرِ وَيُرَخِّصُ فِي مُنَازَعَتِهِمْ إِنَّمَا قِيلَ ذَلِكَ لِلْمَأْمُورِينَ الَّذِينَ قِيلَ لَهُمْ أَطِيعُوا الله وَأَطِيعُوا الرَّسُولَ وَأُولِي الامْرِ مِنْكُمْ.
Hadith No. 2
Al-Husayn ibn Muhammad has narrated from Mu‘alla ibn Muhammad from al-Hassan ibn Ali al-Washsha’ from Ahmad ibn ‘Umar who has said that I asked abu al-Hassan al-Rida about the words of Allah, the Most Holy, the Most High. “Allah (God) commands you to return that which had been entrusted to you to the rightful owners. Be just when passing judgment among people. . .” (4:58) The Imam said, “They are the Imams from the family of Muhammad (s.a.) who are commanded to deliver the trust to the succeeding Imam exclusively and to no one else and that the succeeding Imams must not be deprived of this trust.”
الْحُسَيْنُ بْنُ مُحَمَّدٍ عَنْ مُعَلَّى بْنِ مُحَمَّدٍ عَنِ الْحَسَنِ بْنِ عَلِيٍّ الْوَشَّاءِ عَنْ أَحْمَدَ بْنِ عُمَرَ قَالَ سَأَلْتُ الرِّضَا عَنْ قَوْلِ الله عَزَّ وَجَلَّ إِنَّ الله يَأْمُرُكُمْ أَنْ تُؤَدُّوا الاماناتِ إِلى أَهْلِها قَالَ هُمُ الائِمَّةُ مِنْ آلِ مُحَمَّدٍ ﷺ أَنْ يُؤَدِّيَ الامَامُ الامَانَةَ إِلَى مَنْ بَعْدَهُ وَلا يَخُصَّ بِهَا غَيْرَهُ وَلا يَزْوِيَهَا عَنْهُ.
Hadith No. 3
Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from al-Husayn ibn Sa‘id from Muhammad ibn Fudayl from abu al-Hassan al-Rida about the following words of Allah, the Most Holy, the Most High. “Allah (God) commands you to return that which had been entrusted to you to the rightful owners. Be just when passing judgment among people. . .” (4:58) The Imam said, “They are the Imams . The Imam must deliver the trust to the succeeding Imam exclusively and to no one else and that the succeeding Imams must not be deprived of this trust.”
مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ الْحُسَيْنِ بْنِ سَعِيدٍ عَنْ مُحَمَّدِ بْنِ الْفُضَيْلِ عَنْ أَبِي الْحَسَنِ الرِّضَا فِي قَوْلِ الله عَزَّ وَجَلَّ إِنَّ الله يَأْمُرُكُمْ أَنْ تُؤَدُّوا الاماناتِ إِلى أَهْلِها قَالَ هُمُ الائِمَّةُ يُؤَدِّي الامَامُ إِلَى الامَامِ مِنْ بَعْدِهِ وَلا يَخُصُّ بِهَا غَيْرَهُ وَلا يَزْوِيهَا عَنْهُ.
Hadith No. 4
Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Muhammad ibn Sinan from Ishaq ibn ‘Ammar from ibn abu Ya‘fur from Mu‘alla ibn al-Khunays who has said that I asked abu ‘Abdallah about the words of Allah, the Most Holy, the Most High. “Allah (God) commands you to return that which had been entrusted to you to the rightful owners.. .” (4:58) The Imam said, “it is the command of Allah that the preceding Imam transfer to the succeeding Imam every thing that is with him.”
مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ مُحَمَّدِ بْنِ سِنَانٍ عَنْ إِسْحَاقَ بْنِ عَمَّارٍ عَنِ ابْنِ أَبِي يَعْفُورٍ عَنِ الْمُعَلَّى بْنِ خُنَيْسٍ قَالَ سَأَلْتُ أَبَا عَبْدِ الله عَنْ قَوْلِ الله عَزَّ وَجَلَّ إِنَّ الله يَأْمُرُكُمْ أَنْ تُؤَدُّوا الاماناتِ إِلى أَهْلِها قَالَ أَمَرَ الله الامَامَ الاوَّلَ أَنْ يَدْفَعَ إِلَى الامَامِ الَّذِي بَعْدَهُ كُلَّ شَيْءٍ عِنْدَهُ.
Hadith No. 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 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.”
مُحَمَّدُ بْنُ يَحْيَى عَنْ مُحَمَّدِ بْنِ الْحُسَيْنِ عَنِ ابْنِ مَحْبُوبٍ عَنِ الْعَلاءِ بْنِ رَزِينٍ عَنْ عَبْدِ الله بْنِ أَبِي يَعْفُورٍ عَنْ أَبِي عَبْدِ الله قَالَ لا يَمُوتُ الامَامُ حَتَّى يَعْلَمَ مَنْ يَكُونُ مِنْ بَعْدِهِ فَيُوصِيَ إِلَيْهِ.
Hadith No. 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 who has said the following “The Imam knows the succeeding Imam and delivers his will to him.”
أَحْمَدُ بْنُ إِدْرِيسَ عَنْ مُحَمَّدِ بْنِ عَبْدِ الْجَبَّارِ عَنْ صَفْوَانَ بْنِ يَحْيَى عَنِ ابْنِ أَبِي عُثْمَانَ عَنِ الْمُعَلَّى بْنِ خُنَيْسٍ عَنْ أَبِي عَبْدِ الله قَالَ إِنَّ الامَامَ يَعْرِفُ الامَامَ الَّذِي مِنْ بَعْدِهِ فَيُوصِي إِلَيْهِ.
Hadith No. 7
Ahmad has narrated from Muhammad ibn ‘Abd al-Jabbar from abu ‘Abdallah al-Barqi from Fudalah ibn Ayyub from Sulayman ibn Khalid from abu ‘Abdallah who has said the following. “No scholar (Imam) has ever died before Allah, the Most Holy, the Most High, would grant him the knowledge of to who must he deliver his will.”
أَحْمَدُ عَنْ مُحَمَّدِ بْنِ عَبْدِ الْجَبَّارِ عَنْ أَبِي عَبْدِ الله الْبَرْقِيِّ عَنْ فَضَالَةَ بْنِ أَيُّوبَ عَنْ سُلَيْمَانَ بْنِ خَالِدٍ عَنْ أَبِي عَبْدِ الله قَالَ مَا مَاتَ عَالِمٌ حَتَّى يُعْلِمَهُ الله عَزَّ وَجَلَّ إِلَى مَنْ يُوصِي.