A Narration about Ali, peace be with him
‘Arzamí reported that Abu ‘Abdullah (`a)* said, “‘Alí had a servant whose name was Qanbar. He loved ‘Alí with an intense love. When ‘Alí went out, he would go out after him with a sword. Ali saw him one night. He said to him, ‘O Qanbar! What are you doing?’ ‘I came to walk behind you. Verily, the people are as you see, O Commander of the Faithful! So, I am afraid for you.’ Ali said, ‘Woe is you! Would you protect me from the folk of heaven or from the folk of the earth?’ He said, ‘No, rather from the folk of the earth.’ He said, ‘Verily, the folk of the earth are not capable of doing anything to me except by permission of Allah, the Mighty and Magnificent, from heaven. So, go back!’ So, he returned.”
This narration is from Shaykh Saduq's Tawhid, Bab 55, No. 7.
*(`a) means "peace be with him," `alayhi al-salam.