Umar bin Abd al-Aziz narrates from his father; the narrator says: I think he also mentioned his grandfather; (he narrates:) "The Prophet (peace and blessings be upon him) was asked: Which Islam is most excellent? He said: That which stands firm on the straight path and is easy."
Imam al-Bazzar recorded it, and its chain contains a narrator, Abd al-Aziz bin Aban, who is a kadhdhab (liar) and a fabricator of narrations.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الإيمان / 206