There is no speaker or listener in true teaching.

It is almost impossible to meet a teacher we can trust and follow for the rest of our lives.

This is because human thoughts, human words, and human minds are not reliable at all. 

It is the same with anyone's heart, if you trust and follow only people, you will be disappointed someday. 

However, don't look at who is saying it, but look at what is saying.

If you're a speaker, you shouldn't say a book or something you've heard from someone in the first place, 

And you should experience it yourself and say something you're sure of.

Otherwise, you should keep in mind that even if you quote Buddha's words without direct experience, 

It may not end with your show off, but may lead to death for followers.

There is a Zen poem in Korea."When you walk on the field covered in snow, shalt not blindly walk, 

Because your footprint today can be a milestone for the next of the people."