Hadith 1:

أَبُو مُحَمَّدٍ جِبْرِيلُ بْنُ مُحَمَّدٍ الْفَارَيَابِيُّ، قَالَ حَدَّثَنِي مُوسَى بْنُ جَعْفَرِ بْنِ وَهْبٍ، قَالَ حَدَّثَنِي أَبُو الْحَسَنِ أَحْمَدُ بْنُ حَاتِمِ بْنِ مَاهَوَيْهِ، قَالَ: كَتَبْتُ إِلَيْهِ‌ يَعْنِي أَبَا الْحَسَنِ الثَّالِثَ (ع) أَسْأَلُهُ عَمَّنْ آخُذُ مَعَالِمَ دِينِي وَ كَتَبَ أَخُوهُ أَيْضاً بِذَلِكَ فَكَتَبَ إِلَيْهِمَا فَهِمْتُ مَا ذَكَرْتُمَا فَاصْمِدَا فِي دِينِكُمَا عَلَى مُسِنٍ‌ (مستن) فِي حُبِّنَا وَ كُلِّ كَبِيرِ (كسير) التَّقَدُّمِ فِي أَمْرِنَا، فَإِنَّهُمْ كَافُوكُمَا إِنْ شَاءَ اللَّهُ تَعَالَى

Narrated that Abu al-Hasan Ahmad bin Hatim bin Mahawayh said,

"I wrote a letter to Abu al-Hasan the third (i.e., Imam Ali Naqi al-Hadi) (عليه السلام) asking Him from whom should I take my religious knowledge. And his brother also wrote the same to the Imam."

So, the Imam (عليه السلام) wrote back to both of them saying, "I have understood what you both have mentioned, So rely/depend in matters of your religion upon the one who has spent is life (i.e. aged) in Our Love and all those who are firm/deeply rooted in Our matters/commands, as they will be sufficient for you, In-Sha-Allah."

[Source: Rijal al-Kashshi, Vol, 1, Pg. 16]