'Abdullah bin Mas'ud (May Allah be pleased with him) reported:
Messenger of Allah ﷺ, the truthful and the receiver of the truth informed us, saying, "The creation of you (humans) is gathered in the form of semen in the womb of your mother for forty days, then it becomes a clinging thing in similar (period), then it becomes a lump of flesh like that, then Allah sends an angel who breathes the life into it; and (the angel) is commanded to record four things about it: Its provision, its term of life (in this world), its conduct; and whether it will be happy or miserable. By the One besides Whom there is no true god! Verily, one of you would perform the actions of the dwellers of Jannah until there is only one cubit between him and it (Jannah), when what is foreordained would come to pass and he would perform the actions of the inmates of Hell until he enter it. And one of you would perform the actions of the inmates of Hell, until there is only one cubit between him and Hell. Then he would perform the acts of the dwellers of Jannah until he would enter it."

[Al-Bukhari and Muslim].

وعن ابن مسعود، رضي الله عنه ، قال: حدثنا رسول الله ﷺ، وهو الصادق المصدوق: "إن أحدكم يجمع خلقه في بطن أمه أربعين يوماً نطفةً، ثم يكون علقة مثل ذلك، ثم يكون مضغةً مثل ذلك، ثم يرسل الملك، فينفخ فيه الروح، ويؤمر بأربع كلمات: يكتب رزقه، وأجله، وعمله، وشقى أم سعيد. فوالذي لا إله غيره إن أحدكم ليعمل بعمل أهل الجنة حتى ما يكون بينه وبينها إلى ذراع، فيسبق عليه الكتاب ، فيعمل بعمل أهل النار فيدخلها، وإن أحدكم ليعمل بعلم أهل النار حتى ما يكون بينه وبينها إلا ذراع، فيسبق عليه الكتاب فيعمل بعمل أهل الجنة فيدخلها" ((متفق عليه)) .