You searched for: “de mortuis nihil nisi bonum
De mortuis nihil nisi bonum.
Of the dead, (say) nothing but good.

Another translation: "Speak kindly of the dead." It is believed that Chilon of Sparta, one of the wise men of sixth-century B.C. Greece, is the author of this saying. Keep in mind that this would be a Latin translation of what Chilon said in Greek.

The advice to everyone is to speak well of the recently dead or, if you can not say anything good, to keep quiet.