Musannaf Ibn Abi Shayba 17:1278

Affan narrated to us, he said: Abd al-Aziz ibn Muslim narrated to us, from al-A'mash, from Ibrahim, from Alqama, from Abdullah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "No one shall enter Paradise who has in his heart the weight of a mustard seed of pride, and no one shall enter the Fire who has in his heart the weight of a mustard seed of faith."