The owner of this house, that is, Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), said: I asked the Messenger of Allah (peace and blessings be upon him): O Messenger of Allah, which deed is the most excellent? He said: "Performing the prayer at its time." I said: Then what, O Messenger of Allah? He said: "Kindness to parents." I said: Then what, O Messenger of Allah? He said: "That people are safe from your tongue." Then he (peace and blessings be upon him) fell silent, and had I asked him for more, he (peace and blessings be upon him) would have told me more.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9766