Here is a Ḥasan (Good) ḥadīth that says there is no authority and knowledge except that it comes from the Ahl al-Bayt (عليهم السلام). Also, within this ḥadīth is the famous mutawātir ḥadīth of Imām `Alī (عليه السلام) where he tells the people “Salūnī (Ask me) whatever you wish”.
عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ ابْنِ أَبِي نَصْرٍ عَنْ مُثَنًّى عَنْ زُرَارَةَ قَالَ كُنْتُ عِنْدَ أَبِي جَعْفَرٍ ع فَقَالَ لَهُ رَجُلٌ مِنْ أَهْلِ الْكُوفَةِ يَسْأَلُهُ عَنْ قَوْلِ أَمِيرِ الْمُؤْمِنِينَ ع سَلُونِي عَمَّا شِئْتُمْ فَلَا تَسْأَلُونِّي عَنْ شَيْءٍ إِلَّا أَنْبَأْتُكُمْ بِهِ قَالَ إِنَّهُ لَيْسَ أَحَدٌ عِنْدَهُ عِلْمُ شَيْءٍ إِلَّا خَرَجَ مِنْ عِنْدِ أَمِيرِ الْمُؤْمِنِينَ ع فَلْيَذْهَبِ النَّاسُ حَيْثُ شَاءُوا فَوَ اللَّهِ لَيْسَ الْأَمْرُ إِلَّا مِنْ هَاهُنَا وَ أَشَارَ بِيَدِهِ إِلَى بَيْتِهِ
From Zurārah said, I was with Abī Ja`far (عليه السلام) and a man from the people of al-Kūfa asked him about the saying of Amīr al-Mu’minīn (عليه السلام), ‘Salūnī (Ask me) whatever you wish, and you will not ask me about a thing except that I inform you of it’. He (عليه السلام) said: ‘No one has with him knowledge of a thing except that is comes from Amīr al-Mu’minīn (عليه السلام). So people can go wherever they desire, by Allāh, there is no authority (right) except from here, and he pointed with his hand to his house (i.e. Ahl al-Bayt (عليهم السلام))’
Source:
1. Al-Kulaynī, Al-Kāfī, ed. `Alī Akbar al-Ghaffārī, 8 vols., (Tehran: Dār al-Kutub al-Islāmiyyah, 3rd Edition, 1388 AH), vol. 1, pg. 399, ḥadīth # 2
Grading:
1. Al-Majlisī said this hadeeth is Ḥasan (Good)
à Mir’āt Al-`Uqūl, 26 vols., (Tehran: Dār al-Kutub al-Islāmiyyah, 1410 AH), vol. 4, pg. 308
à Mir’āt Al-`Uqūl, 26 vols., (Tehran: Dār al-Kutub al-Islāmiyyah, 1410 AH), vol. 4, pg. 308