Al-Walid bin al-Ayzar said: I heard Abu Amr al-Shaybani say: The owner of this house told me, and he pointed towards the house of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), that he said: I asked the Prophet (peace and blessings be upon him): "Which deed is most beloved to Allah Almighty?" He (peace and blessings be upon him) said: "Offering the prayer at its time." I asked: "Then which deed?" He (peace and blessings be upon him) said: "Treating one's parents well." I asked: "Then which?" He said: "Jihad in the path of Allah." Ibn Mas'ud (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) told me these three things; had I asked for more, he (peace and blessings be upon him) would have told me more.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3165