Do not explain the teachings without being requested to do so;  as Gunaprabha’s Sutra on the Discipline (Vinaya-sutra) says, “It should not be done without a request.”  …[Yet] Concerning this, the King of Concentration Sutra says:

Should someone request you

To bestow the teachings, first say,

“I am not trained extensively.”

Then say, “You are knowledgeable and wise.

How can I explain the teachings

To one as great as you.”

Do not impart the teachings casually,

But only after you have investigated whether the listener is a suitable recipient,

If you know the listener is a suitable recipient,

Explain the teachings even without a request.

-The Great Treatise on the Stages of the Path to Enlightenment

The teachings, like any good advise, depend on heart to heart transfer.  As Seneca wrote, “Philosophy is good advice, and no one gives good advice at the top of his lungs.”  Therefore “Associate with people who are likely to improve you. Welcome those whom you are capable of improving. The process is a mutual one. People learn as they teach.”

-Seneca, Letters From a Stoic