A number of traditions have come down to us which speak of the Holy Prophet's assessment of Umar.
Before the conversion of Umar to Islam, the prayer of the Holy Prophet is on record wherein he prayed "O God, glorify Thy faith by the conversion of Umar."
There is a tradition that when Umar was converted to Islam the Holy Prophet said that Gabriel had visited him to say "O Muhammad, verily the dwellers in Heaven rejoice with you at the conversion of Umar."
According to Abu Hurrayrah, the Holy Prophet once related a dream in the presence of Umar. The Holy Prophet related, "While I was asleep, I saw myself in paradise, and beheld there a woman performing her ablutions by the side of a house. I enquired whose house it was, and I was told that it was Umar's. The lady said that she belonged to Umar. Then recollecting how jealous Umar was in the matter of women, I turned back, and thereafter I woke up". Hearing this, Umar said, "O Prophet of God, everything of mine is at your service; how can I be jealous of you in any matter?"
On another occasion, the Holy Prophet had another dream. He related:
"While I was asleep, I dreamt that I drank milk. Then that milk began to flow from my fingers. That milk I asked Umar to drink, and he drank to his fill." The Holy Prophet was asked to interpret the dream and he said that the dream signified that among his followers, Umar would excel every one in knowledge.
According to another tradition, the Holy Prophet said, "While I was asleep, I saw the people presented to me. These people wore garments. Some had garments reaching to their breasts, and some had garments which reached their toes. Then Umar was presented, and upon him was a garment which was so long that he dragged it as he moved". The Holy Prophet was requested to interpret the dream. The Holy Prophet said that the significance of the dream was that Umar would be a source of strength and service to Islam.
Al-Bukhari carries a tradition according to which the Holy Prophet said that there was to be no prophet after him, but if there were to be no bar to such prophethood, Umar would have been the prophet. That was the highest tribute that the Holy Prophet could pay to Umar.
According to another tradition the Holy Prophet said, "Verily God has placed truth upon the tongue of Umar, and upon his heart." According to an allied tradition, the Holy Prophet said, "Never did a thing come upon the people, and they said one thing regarding it, and Umar another, but the Qur'an revealed it after the manner that Umar had said. The greatest tribute was paid to Umar, when the Holy Prophet said, "God speaks through the tongue of ;Umar."
There is a tradition that Gabriel once came to the Holy Prophet and said, "Greet Umar with a salutation, and tell him that his anger is glory and his approval, command."
According to a tradition, the Holy Prophet said, "Umar is the lamp of the dwellers in paradise."
A tradition is on record according to which pointing to Umar the Holy Prophet said, "Umar is a strongly bolted gate against discord. As long as he lives in your midst, there will be no discord among the Muslims."
We have it on the authority of 'Ayesha that the Holy Prophet said, "Verily I behold the evil spirits among genii and men, fleeing from Umar". In the same strain the Holy Prophet said, "Verily Satan avoideth Umar."
There is another tradition according to which the Holy Prophet said, "There is not an angel in Heaven, but he revereth Umar, and not a demon on earth but he fleeth from Umar.",
On the occasion of the last pilgrimage the Holy Prophet said, "Verily God approved of the conduct of the pilgrims at Arafat in general and Umar in particular".
There is a tradition that in the days of his illness the Holy Prophet said, "The Truth after me is with Umar, wherever he may be."
About Umar's victory against Satan, the Holy Prophet said, "Verily Satan hath never met Umar since his conversion, but he hath fallen prostrate on his face."
According to a tradition the Holy Prophet said, "Gabriel said to me, 'verily Islam will weep at the death of Umar."
According to a tradition the Holy Prophet expressed his attachment to Umar in the following terms: "He who hateth Umar hates me, and he who loveth Umar loves me".