When do Muslims believe Jibril first appeared?

Muslims believe Jibril first appeared to Muhammed when he was a child. When Jibril and Mika’ il came to Muhammed they purified his heart so he could receive God’s revelation later in life. So when Muhammed was 40, Jibril returned to him, told him what God wanted him to do, and inspired him with the revelations of the Qur’an. Muslims believe God continued to guide Muhammed throughout his life, using Jibril as a communicator