Sahih al-Bukhari 2912

It is related that 'Abdullah said, "The Messenger of Allah, may Allah bless him and grant him peace, who is the truthful confirmed one, said, 'The way that each of you is created is that you are gathered in your mother's womb for forty days as a sperm-drop and then for a similar length of time as a blood-clot and then for a similar length of time as a lump of flesh. Then an angel is sent and he breathes the spirit into you and is encharged with four commandments: to write down your provision, your life-span, your actions, and whether you will be wretched or happy. Then the spirit is breathed into him. So a man among you may do the actions of someone destined for the Garden until there is only an armspan between him and it, and then what is written will overtake him and he will do the actions of someone destined for the Fire . A man among you may do the actions of someone destined for the Fire until there is only an armspan between him and it, and then what is written will overtake him and he will do the actions of someone destined for the Garden.'"