The Messenger of Allah ﷺ said, "No one will enter the Fire who has in his heart the weight of a mustard seed of faith, and no one will enter Paradise who has in his heart the weight of a mustard seed of pride."
قال رسول الله ﷺ: لا يدخل النار أحد في قلبه مثقال حبة خردل من إيمان. ولا يدخل الجنة أحد في قلبه مثقال حبة خردل من كبرياء.
Muslim reported it in the Book of Faith (91:148) through several routes from Ali bin Mushir, from Amash, from Ibrahim, from Alqama, from Abdullah bin Masud, who narrated it.