Three questions to be put to ourselves before speaking evil of any man:
“First, is it true? Second, is it kind? Third, is it necessary?”
Lots of people say it is from Buddha but someone says it is a fake Buddha quote. One say from Poynder’s Literary Extracts), and that quotation itself is was from a Reverend Mr. Stewart.
But it is widely accepted that the thought or originate influence would be from Buddha’s teachings.
As Buddha’s guidelines for speech were more like five –
That speech should be true, kind, helpful, conducive to harmony, and spoken at the right time.
However old it this is, I think it is timeless teaching.