Surah Fussilat, Verse 33
Translation — Sahih International
And who is better in speech than one who invites to Allah and does righteousness and says, "Indeed, I am of the Muslims."
Source
Kur'an-ı Kerim, Fussilet Suresi 41:33
https://kuran.diyanet.gov.tr/mushaf/kuran-meal-2/41-suresi-33-ayet