A Pure, Clear Confidence

Anyone who, even for a second, feels a pure, clear confidence on hearing the truth will experience immeasurable happiness. Why? Because, at that moment, that person is not caught up in the concept of a self or a living being or a life span. He is not caught up in concepts about the world, nor is he caught up in concepts about nothingness. He does not take any notice of the idea that this is a sign, or this or that is not a sign.

For if you are caught up in ideas, then you will be caught up in the self. And even if you are caught up in ideas about nothingness, you will still be caught up in the self. That's why we should not get attached to the belief that things either exist or do not exist. This is the hidden meaning when I say that my teachings are a raft to be abandoned when you see true being.

-Diamond Sutra

The above sutra is from Chapter 6 of the Diamond Sutra.

This sutra is also known as The Vajracchedika Prajnaparamita Sutra.

Here are other versions of the same quote:

Anyone who, for only a second, gives rise to a pure and clear confidence upon hearing these words of the Tathagata, the Tathagata sees and knows that person, and he or she will attain immeasurable happiness because of this understanding. Why?

"Because that kind of person is not caught up in the idea of a self, a person, a living being, or a life span. They are not caught up in the idea of a dharma or the idea of a non-dharma. They are not caught up in the notion that this is a sign and that is not a sign. Why? If you are caught up in the idea of a dharma, you are also caught up in the ideas of a self, a person, a living being, and a life span. If you are caught up in the idea that there is no dharma, you are still caught up in the ideas of a self, a person, a living being, and a life span. That is why we should not get caught up in dharmas or in the idea that dharmas do not exist. This is the hidden meaning when the Tathagata says,'Bhiksus, you should know that all of the teachings I give to you are a raft.
--The Vajracchedika Prajnaparamita Sutra

References:

The Vajracchedika Prajnaparamita Sutra:
http://www.sinc.sunysb.edu/Clubs/buddhism/sutras/diamond1.html

The Vajracchedika Prajna paramita Sutra (The Diamond Sutra):
http://www.buddhistinformation.com/diamondsutra.htm