Here are two details of the conversation between Muhammad (pbuh) and Jibrail in the cave of Hira:
**1. Muhammad (pbuh) was asked to read.**
Jibrail appeared to Muhammad (pbuh) and said, "Read!" Muhammad (pbuh) replied, "I cannot read." Jibrail then embraced him tightly and then revealed to him the first lines of chapter 96 of the Quran, "Read in the name of your Lord Who created, (1) Created man from a clot. (2) Read: And your Lord is the Most Generous, (3) Who taught by the pen, (4) Taught man that which he knew not. (5)" (Bukhari 4953)
**2. Muhammad (pbuh) was told that he was the Messenger of Allah.**
After Muhammad (pbuh) recited the first lines of the Quran, Jibrail said to him, "O Muhammad, you are the Messenger of Allah and I am Jibril." (Bukhari 4953)
These two details show the beginning of Muhammad's (pbuh) prophethood and the revelation of the Quran. They are also two of the most important events in Islamic history.
I hope this helps!