It is reported in the Musnad of Ahmad from Anas, radi Allahu anhu, that he said:
"We were sitting in the presence of Rasulullah sallallahu alayhi wa sallam one day and he said, ‘A person is about to arrive from this mountain path who is from the people of Paradise.’
So a person from the Ansar arrived, his beard dripping with water from wudoo and holding his sandals in his left hand, and he gave us the salaam.
Then next day the Prophet sallallahu alayhi wa sallam said words of similar import and the same person appeared in the same condition. On the third day Rasulullah sallallahu alayhi wa sallam again said words of similar import and again this person appeared in the same condition, so when Rasulullah sallallahu alayhi wa sallam left, ‘Abdullah bin ‘Amr bin al-Aas followed this person and said, ‘Indeed I have abused my father and I swear that I would not go to him for three days so if you would let me stay with you until those three days expire, I would do so.’ He replied, ‘Yes.’"
Anas continued saying, "So ‘Abdullah told us that he spent three nights with this person yet he did not see him stand for the night prayer at all. All he did was when he turned sides on his bed he would mention Allah and make takbeer and would do this until he stood for fajr prayer.’ Abdullah said, ‘Except that I never hear him speak except good‘. So when the three days were over I was eager to make little of his actions. I said, ‘O servant of Allah there was no hatred or disassociation between my father and me but I heard Rasulullah sallallahu alayhi wa sallam saying on three occasions, "A person is about to arrive who is from the people of Paradise," and you arrived on those three occasions, so I wished to stay with you so that I may look at your actions and emulate them. But I have not seen you perform a great deal of actions, so what is it that has reached you to make Rasulullah sallallahu alayhi wa sallam say what he said?’ He replied, ‘It is nothing more than what you have seen, except that I do not find in myself any disloyalty to any of the Muslims, and neither do I find any jealousy for the wealth that Allah has bestowed upon them.’ Abdullah said, ‘This is that which has reached you and is something that we cannot endure.’"
This hadith is authentic and classified as hassan. It is narrated in Musnad Imam Ahmed, and Albazar as well as others in many different chains.