“It is spoken at the right time. It is spoken in truth. It is spoken affectionately. It is spoken beneficially. It is spoken with a mind of good will.” — Anguttara Nikaya 5.198
Here’s an except that helps us consider what is worth saying. It’s based on considering three things: is what you are going to say TRUE, is it BENEFICIAL, and is it WELCOME?
And then there’s TIMING
“Such speech as the Tathagata knows to be untrue, incorrect, and unbeneficial, and which is also unwelcome and disagreeable to others: such speech the Tathagata does not utter.
Such speech as the Tathagata knows to be true and correct but unbeneficial, and which is also unwelcome and disagreeable to others: such speech the Tathagata does not utter.
Such speech as the Tathagata knows to be true, correct and beneficial, but which is unwelcome and disagreeable to others: the Tathagata knows the time to use such speech.
Such speech as the Tathagata knows to be untrue, incorrect, and unbeneficial, but which is welcome and agreeable to others: such speech the Tathagata does not utter.
Such speech as the Tathagata knows to be true and correct but unbeneficial, and which is welcome and agreeable to others: such speech the Tathagata does not utter.
Such speech as the Tathagata knows to be true, correct and beneficial, and which is welcome and agreeable to others: the Tathagata knows the time to use such speech.
Why is that? Because the Tathagata has compassion for sentient beings.” — Majjhima Nikaya 58