رسول الله صَلَّي اللهُ عَلَيْهِ وَ آلِهٖ أَنَا مَدِينَةُ الْعِلْمِ وَ عَلِيٌّ بَابُهَا فَمَنْ أَرَادَ الْمَدِينَةَ فَلْيَأْتِ الْبَاب
The Messenger of Allah (peace be on him and his progeny) declared,
“I am the city of knowledge and Ali is its door. So, whoever intends to (enter) the city, then he must come through the door.”
References:
1. Al-Fusool al-Mukhtaarah, pp. 220 and 224
2. Kashf al-Ghummah, vol. 1, p. 113 quoting Hilyah al-Awliyaa of Hafiz Abu Noaim al-Isfahani and al-Tirmidhi in his Sunan