Courtesy

{16:125} Call to the way of your Lord with wisdom and goodly exhortation, and have disputations with them in the best manner; surely your Lord best knows those who go astray from His path, and He knows best those who follow the right way.

{4:86} and when you are greeted with a greeting, greet with a better (greeting) than it or return it; surely Allah takes account of all things.

{25:63} and the servants of the Beneficent Allah are they who walk on the earth in humbleness, and when the ignorant address them, they say: Peace.

{17:53} and say to my servants (that) they speak that which is best; surely the Shaitan sows dissensions among them; surely the Shaitan is an open enemy to man.

{31:19} and pursue the right course in your going about and lower your voice; surely the most hateful of voices is braying of the asses.