One of the best narrations ever, and it is sound/authentic (Sahih):
Sayyiduna ‘Ali ibn Abi Talib, Alayhis Salam, said concerning his spiritual companionship [Suhba] with the Prophet Muhammad ﷺ,
“I was still a young child and the Prophet ﷺ took me into his custody. I used to cling to him and he used to feed me.
As I grew up, he saw that I never uttered a lie, nor did I ever try to deceive people.
It was because in my eyes, the Prophet ﷺ was my guiding star, and I used to follow his actions and deeds very carefully.
You could say, I was attached to him like a foal of camel are attached to their mother.
On top of that, he ﷺ used to place before me high values of morality, and he ﷺ used to advise me to follow them.
Every year, he would spend a few days at the grotto of the Mount Hira and I used to accompany him.
In fact, I was his only companion then, and nobody was permitted to enter or meet him there at the grotto of Hira.
It was there that I used to see the light of revelation come down and I used to smell the fragrance of Prophet-hood upon the Prophet Muhammad.
Once the Prophet ﷺ himself told me:
“O Ali! You have attained a very high station with Allah. You see what I see and you hear what I hear.”
(Recorded in the Hilyatul Awliyah of Imam Abu Nu’aym Al-Asbahani ~ Also related in the Tafsir ad-Durr Al-Manthur by Imam Jalaludin Al-Suyuti)