Guru Nanak, Sri Guru Granth Sahib had said many things to giver of peace , what he said read it here:

“Burn worldly love, rub the ashes and make ink of it, make the heart the pen, the intellect the writer, 
write that which has no end or limit.” ― Guru Nanak, Sri Guru Granth Sahib

“He who has no faith in himself can never have faith in God.” ― Guru Nanak, Sri Guru Granth Sahib

“The world is a drama, staged in a dream” ― Guru Nanak, Sri Guru Granth Sahib

“Speak only that which will bring you honor.” ― Guru Nanak, Sri Guru Granth Sahib

“For each and every person, our Lord and Master provides sustenance. Why are you so afraid, O mind? The flamingos fly hundreds of miles, leaving their young ones behind. Who feeds them, and who teaches them to feed themselves? Have you ever thought of this in your mind?” ― Guru Nanak, Sri Guru Granth Sahib

“Even kings and emperors, with mountains of property and oceans of wealth - these are not even equal to an ant, who does not forget God.” ― Guru Nanak, Sri Guru Granth Sahib

“Your Mercy is my social status.” ― Guru Nanak, Sri Guru Granth Sahib