The Prophet ﷺ said, "Modesty and reserved speech are two branches of faith, while obscenity and excessive eloquence are two branches of hypocrisy."
حدثنا حسين بن محمد وغيره قالا حدثنا محمد بن مطرف عن حسان بن عطية
عن النبي ﷺ قال الحياء والعي شعبتان من الإيمان والبذاء والبيان شعبتان من النفاق
Its chain of transmission is sahih. Tirmidhi reported the hadith with similar wording, 4/329, no. 2027, in the chapter on righteousness, what has been said about verbosity. He said, hasan gharib. Hakim also reported it, 1/9, and graded it sahih, and Dhahabi agreed with him. Haythami said, 1/92, its narrators are the narrators of the Sahih.