Hadith 1:

حَدَّثَنا تَمِيمُ بْنِ عَبْدِ اللَّه بْنِ تَمِيمُ القُرَشِي قالَ حَدَّثَني أَبي، عَن أَحْمَدِ بْنِ عَلِى الأَنْصـارِي عَنْ أَبي الصَّـلْتِ الهَرَوِيِّ قـالَ: قَـالَ الْمَـأْمُونُ يَوْماً لِلرِّضَا عَلَيْهِ السَّلامُ: يَا أَبَا الْحَسَنِ أَخْبِرْنِي، عَن جَدِّكَ أَمِيرِ الْمُؤْمِنِينَ عَلِيِّ بْنِ أَبِي طَالِبٍ‏ عَلَيْهِ السَّلامُ بِأَيِّ وَجْهٍ هُوَقَسِيمُ الْجَنَّةِ وَالنَّارِ وَبِأَيِّ مَعْنَى فَقَدْ كَثُرَ فِكْرِي فِي ذَلِكَ فَقَالَ لَهُ الرِّضَا عَلَيْهِ السَّلامُ يَا أَمِيرَ الْمُؤْمِنِينَ أَلَمْ تُرْوَعَنْ أَبِيكَ، عَن آبَائِهِ، عَن عَبْدِ اللَّهِ بْنِ عَبَّاسٍ أَنَّهُ قَالَ سَمِعْتُ رَسُولَ اللَّهِ‏ صَلَّى اللهُ عَلَيْهِ وَآلِهِ يَقُولُ حُبُّ عَلِيٍّ إِيمَانٌ وَبُغْضُهُ كُفْرٌ فَقَالَ بَلَى فَقَالَ الرِّضَا عَلَيْهِ السَّلامُ فَقِسْمَةُ الْجَنَّةِ وَالنَّارِ إِذَا كَانَتْ عَلَى حُبِّهِ وَبُغْضِهِ فَهُوَقَسِيمُ الْجَنَّةِ وَالنَّارِ فَقَالَ الْمَأْمُونِ لا أَبْقَانِيَ اللَّهُ بَعْدَكَ يَا أَبَا الْحَسَنِ أَشْهَدُ أَنَّكَ وَارِثُ عِلْمِ رَسُولِ اللَّهِ‏ صَلَّى اللهُ عَلَيْهِ وَآلِهِ قَالَ أَبُو الصَّلْتِ الْهَرَوِيُّ فَلَمَّا انْصَرَفَ الرِّضَا إِلَى مَنْزِلِهِ أَتَيْتُهُ فَقُلْتُ لَهُ يَا ابْنَ رَسُولِ اللَّهِ مَا أَحْسَنَ مَا أَجَبْتَ بِهِ أَمِيرَ الْمُؤْمِنِينَ فَقَالَ لِي الرِّضَا عَلَيْهِ السَّلامُ إِنَّمَا كَلَّمْتُهُ مِنْ حَيْثُ هُوَوَلَقَدْ سَمِعْتُ أَبِي يُحَدِّثُ، عَن آبَائِهِ، عَن عَلِيٍ‏ عَلَيْهِ السَّلامُ أَنَّهُ قالَ: قالَ لِي رَسُولُ اللَّهِ‏ صَلَّى اللهُ عَلَيْهِ وَآلِهِ‏يَا عَلِيُّ أَنْتَ قَسِيمُ الْجَنَّةِ وَالنَّارِ يَوْمَ الْقِيَامَةِ تَقُولُ لِلنَّارِ هَذَا لِي وَهَذَا لَكَ

Tamim ibn Abdullah ibn Tamim al-Qurashi narrated that his father quoted on the authority of Ahmad ibn Ali Al-Ansari, that Abi Salt al-Harawi said, “One day Al-Mamun told Al-Reza (ع):

"O Abal Hassan Al-Reza (ع)! Tell me, why is it that your grandfather Amir al-Momineen Ali (ع) became the one to divide up Paradise and Hell. What is meant by this? I have thought a lot about this."

Imam al-Reza (ع) told him, Has it not been narrated by your father, on the authority of your forefathers, on the authority of Abdullah ibn Abbas to have said that he had heard Messenger of Allah (ص) say, "Love of Ali is faith, and hating Him is Kufr (disbelief)."

Al-Mamun said, "Yes."

Then Al-Reza (ع) added, "Therefore, the distribution of Heaven and Hell is based upon Loving Him and hating Him, hence in this way Imam Ali (ع) is the one who divide heaven and hell."

Then Al-Mamun said, "O Abal Hasan (Al-Reza)! May Allah not let me live after you! I testify that you are the inheritor of the knowledge of Messenger of Allah (ص)."

Abi Salt (al-Harawi) added, "When Al-Reza (ع) returned home, I went to see Him and said, “O son of Messenger of Allah! How nice did you respond to al-Mamun's question!"

Al-Reza (ع) said, "O Aba Salt! I answered him using the same way that he was reasoning. I heard my father narrate on the authority of his forefathers, on the authority of Ali (ع) that Messenger of Allah (ص) told him, "O Ali! You are the one to divide up Paradise and Fire on the Resurrection Day. You will tell the fire, this is for Me (leave it) and this is for You (take it)."

[Source: Uyun al-Akhbar Al-Reza, Chapter. 32, Hadees. 30]

Note: This narration is a great piece of show of Wisdom by Imam Ali bin Musa Al-Reza (ع). The last piece of narration is in direct conformity with the narration of Prophet Muhammad (ص) as below:

قال حدثني المظفر بن محمد الوراق قال حدثنا أبو علي محمد بن همام قال حدثنا أبو سعيد الحسن بن زكريا البصري قال حدثنا عمر بن المختار قال حدثنا أبو محمد البرسي عن النضر بن سويد عن عبد الله بن مسكان عن أبي بصير عن أبي جعفر محمد الباقر عن آبائه ع قال قال رسول الله ص كيف بك يا علي إذا وقفت على شفير جهنم و قد مد الصراط و قيل للناس جوزوا و قلت لجهنم هذا لي و هذا لك فقال علي ع يا رسول الله و من أولئك قال أولئك شيعتك معك حيث كنت

Hadith 2:

Part of a longer hadith as narrated from Abu Abd-Allah Imam Sadiq (عليه السلام),

فَقُلْتُ لَهُ يَا ابْنَ رَسُولِ اللَّهِ فَعَلِيُّ بْنُ أَبِي طَالِبٍ (ع) يُدْخِلُ مُحِبَّهُ الْجَنَّةَ وَ مُبْغِضَهُ النَّارَ أَوْ رِضْوَانُ وَ مَالِكٌ فَقَالَ يَا مُفَضَّلُ أَ مَا عَلِمْتَ أَنَّ اللَّهَ تَبَارَكَ وَ تَعَالَى بَعَثَ رَسُولَ اللَّهِ (ص) وَ هُوَ رُوحٌ إِلَى الْأَنْبِيَاءِ (ع) وَ هُمْ أَرْوَاحٌ قَبْلَ خَلْقِ الْخَلْقِ بِأَلْفَيْ عَامٍ فَقُلْتُ بَلَى قَالَ أَ مَا عَلِمْتَ أَنَّهُ دَعَاهُمْ إِلَى تَوْحِيدِ اللَّهِ وَ طَاعَتِهِ وَ اتِّبَاعِ أَمْرِهِ وَ وَعَدَهُمُ الْجَنَّةَ عَلَى ذَلِكَ وَ أَوْعَدَ مَنْ خَالَفَ مَا أَجَابُوا إِلَيْهِ وَ أَنْكَرَهُ النَّارَ قُلْتُ بَلَى قَالَ أَ فَلَيْسَ النَّبِيُّ (ص) ضَامِناً لِمَا وَعَدَ وَ أَوْعَدَ عَنْ رَبِّهِ عَزَّ وَ جَلَّ قُلْتُ بَلَى- قَالَ أَ وَ لَيْسَ عَلِيُّ بْنُ أَبِي طَالِبٍ خَلِيفَتَهُ وَ إِمَامَ أُمَّتِهِ قُلْتُ بَلَى قَالَ أَ وَ لَيْسَ رِضْوَانُ وَ مَالِكٌ مِنْ جُمْلَةِ الْمَلَائِكَةِ وَ الْمُسْتَغْفِرِينَ لِشِيعَتِهِ النَّاجِينَ بِمَحَبَّتِهِ قُلْتُ بَلَى قَالَ فَعَلِيُّ بْنُ أَبِي طَالِبٍ إِذَنْ قَسِيمُ الْجَنَّةِ وَ النَّارِ عَنْ رَسُولِ اللَّهِ (ص) وَ رِضْوَانُ وَ مَالِكٌ صَادِرَانِ عَنْ أَمْرِهِ بِأَمْرِ اللَّهِ تَبَارَكَ وَ تَعَالَى يَا مُفَضَّلُ خُذْ هَذَا فَإِنَّهُ مِنْ مَخْزُونِ الْعِلْمِ وَ مَكْنُونِهِ لَا تُخْرِجْهُ إِلَّا إِلَى أَهْلِهِ

Mufaddal Bin Umar (the narrator) said, "I said to the Imam, ‘O Son of Rasool-Allah (عليه السلام) So, Ali ibn Abi Talib (عليه السلام) will be entering His friends into the Paradise and His haters into the Fire, or would it be Ridwan (gatekeeper of Paradise) and Maalik (gatekeeper of Hell)?"

Imam (عليه السلام) said, "O Mufaddal! Don’t you know that Allah (تبراك و تعالى) sent the Messenger of Allah (صلى الله عليه وآله) while He was a soul (rooh), to the Prophet while they were souls, two thousand years before the creation of the creations?"

I (the narrator) said, "Yes".

Imam (عليه اسلام) said, "Don’t you know that the Prophet (صلى الله عليه وآله) called them to Unity of Allah (Tawheed) and obeying Him and following His command (amr) and He promised them Paradise upon that, and threatened the one who opposed it and denied it, with fire?"

I (the narrator) said, "Yes".

Imam (عليه السلام) said, "And is the Prophet (صلى الله عليه وآله) not responsible for what He has promised and threatened on behalf of His Lord (عز وجل)?"

I (the narrator) said, "Yes".

Imam (عليه السلام) said, “And is Ali ibn Abi Talib (عليه السلام) not the caliph of the Prophet and the leader (Imam) of the His community?”

I (the narrator) said, "Yes".

Imam (عليه السلام) said, “Aren't Ridwan and Malik among the angels and those who seek forgiveness for His followers who are saved due to his love?”

I (the narrator) said, "Yes".

Imam (عليه السلام) said, “So, Ali ibn Abi Talib (عليه السلام) then is distributor of the Paradise and the Fire on behalf Prophet of Allah (صلى الله عليه وآله), and Ridwaan and Maalik are two implementers of His orders by the command of Allah (تبارك و تعالى).

Imam (عليه السلام) then said, "O Mufaddal, Take hold of this, for it is from amongst the treasured & the hidden knowledge and do not bring it out except to those who are worthy/deserving of it."

[Source: elal al-Sharayie, Shaikh Sadooq, Vol. 1, Pg. 163]