The Book Pertaining to Judicial Decisions (Kitab Al-Aqdiyya)
Muslim :: Book 18 : Hadith 4259
Sha'bi reported that the scribe of al-Mughira b. Shu'ba said: Mu'awiya wrote to Mughira: Write for me something which you heard from Allah's Messenger (may peace be upon him) ; and he wrote: I heard Allah's Messenger (may peace be upon him) as saying. Verily Allah disapproves three thingq for you: irrelevant talk, wasting of wealth and persistent questioning.