8.
The Discourse on Speech
198.
"Monks, speech possessed of five factors is well spoken, not badly spoken, blameless and beyond reproach by the wise.
Which five?
It is spoken at the proper time, it is spoken truthfully, it is spoken smoothly, it is spoken beneficially, and it is spoken with a mind of friendliness.
Monks, speech possessed of these five factors is well spoken, not badly spoken, blameless and beyond reproach by the wise."
The eighth.