In Sahih Bukhari and Sahih Muslim, there is a long narration from Umm Al-Mumineen Hazrat Ayesha (may Allah be pleased with her) about the revelation.

First of all, we started with congratulations and dreams for the Holy Prophet (sws). So whatever dream you had would be as bright and clear as the morning light. Then the Prophet (peace and blessings of Allaah be upon him) loved solitude and loneliness. Before returning, he would spend many nights in worship and for this, he would take Tosha.
Then they would come to Hazrat Khadijatah Al-Kubra and then they would leave with their blankets until suddenly the truth came to the Prophet (peace be upon him). At that time he was in the Cave of Hira. And began to say. Read on The Prophet (peace and blessings of Allah be upon him) said: I am not educated. The Prophet (peace and blessings of Allah be upon him) said: This angel grabbed me and pressed me hard, which caused me great pain. Then he released me and said:

۔ Read on! I said I am not educated.

۔ He grabbed me again and pulled me so hard that it hurt so much. Then left and said read! I still said that I was not educated. He pulled hard for the third time. Until the pain reached its peak then he left me and said

The Holy Prophet (peace and blessings of Allah be upon him) took these verses back to Hazrat Khadijah and his heart was trembling because of the greatness of the blessed revelation. You have told Hazrat Khadijat-ul-Kabra to take off the blanket. They tore the blanket. She even passed away from the heart of the Prophet (peace and blessings of Allah be upon him).

It is also clear from this famous and long hadith of Sahih Bukhari and Muslims which verses were first revealed after the Prophet (sws) was given the position of prophethood and prophethood. Imam Bayhaqi (may Allah have mercy on him) has narrated this narration of Hazrat Ayesha Siddiqah (may Allah have mercy on her) in Dalail-ul-Nabwat.