This hadith has become so famous that it has been labeled by some, such as Al-Qurtubi and Ibn Daqiq al-Eid as the core or mother of the Sunnah due to it containing a full and concise summary of the faith. As outlined by Qadi ‘Iyaad, “This hadith includes an explanation of all the duties of worship, whether they be external or internal. [It includes] the tenets of faith, the actions of the limbs, the sincerity of self, and the protection of deeds from the calamity [of not being accepted], to the extent that all Islamic laws (Sharia’h) refer back to it and branch out of it.”
As narrated by Umar Ibn al-Khattab (may Allah be pleased with him) from our beloved Messenger ﷺ:
“While we were one day sitting with the Messenger of Allah, peace and blessings be upon him, there appeared before us a man dressed in extremely white clothes and with pitch black hair. No traces of travel were visible on him, and none of us knew him. He sat down, close to the Prophet (peace be upon him), rested his knee against [the Prophet’s] knees, put his hands on his thighs, and said, "O Muhammad! Inform me about Islam."
The Messenger of Allah, peace be upon him, said, "Islam is that you should testify that there is no god but Allah and that Muhammad is His Messenger, that you should perform prayer, pay the zakat, fast during Ramadan, and perform Hajj to the House (the Kaa’ba), if you are able to do so."
The man said, "You have spoken truly." We were astonished at his asking [the Messenger] and telling him that he was right, but he went on to say, "Inform me about Iman."
[The Messenger of Allah] answered, "It is that you believe in Allah, His angels, His Books, His Messengers, the Last Day, and in qadar (destiny), both in its good and in its evil aspects." [The man] said, "You have spoken truly."
Then [the man] said, "Inform me about Ihsan." [The Messenger of Allah] answered, "It is that you should serve Allah as though you can see Him, for though you cannot see Him, He sees you."
[The man] said, "Inform me about the Hour." [The Messenger of Allah] said, "The one questioned knows no more than the questioner." So [the man] said, "Well, inform me about its signs." [The Messenger of Allah] said, "They are that the slave-girl will give birth to her mistress, and that you will see the barefooted, naked, destitute herdsmen of the sheep (competing with each other) in raising lofty buildings." After that, the man took off. I waited a while, and then [the Messenger of Allah] said, "O Umar, do you know who that questioner was?" I replied, "Allah and His Messenger know better." He said, "That was Jibreel. He came to teach you your religion."