‘Abdallah b. ‘Amr reported God's messenger as saying,“Knowledge has three categories:a precise verse, or an established sunna, or a firm obligatory duty. Anything else is an extra.”Abu Dawud and Ibn Majah transmitted it.

‘Auf b. Malik al-Ashja‘i reported God’s messenger as saying, "Only a ruler, or one put in charge, or one who is presumptuous gives instruction."* Abu Dawud transmitted it,

and Darimi transmitted it from ' Amr b. Shu'aib from his father from his grandfather. A version has, "Or a hypocrite”instead of "one who is presumptuous”. *The word used here is yaqussu, which may be translated as given above, but which may also be translated as“inflicts punishment.”