Hadith #1977 (Jami' al-Tirmidhi)
Book: Chapters on Righteousness And Maintaining Good Relations With Relatives
Narrator(s): Anas ibn Malik, Ubaid bin Waqd al-Qaysy عبيد بن واقد القيسي

“The best of you are those best in conduct.’ And the Prophet was not one who was obscene, nor one who uttered obscenities.”

Source: https://parallelquran.com/hadith/jami-al-tirmidhi-1977/