The Buddha recognized this problem and specified that teachings on emptiness be given only to a selective audience. To receive the teachings, one must have the right disposition. There are rules on who can listen to the teachings and who cannot.

In Introduction to the Middle Way, it is said everyone is endowed with two kinds of root virtue or capacity: one is the wisdom of emptiness, the other the accumulation of merit – also known as the roots of wisdom and skillful means. One can receive the teachings on emptiness only when his or her wisdom capacity is mature.

What are the perceptible signs of mature wisdom root in a person? If upon hearing the teachings of emptiness, a person exudes great confidence with tears running down the face and the hair on the body standing up – these are signs of mature root of wisdom. A person of this capacity will quickly realize emptiness when he or she receives the teachings. So it is necessary to give the teaching in this case.

- Quote from The Four Seals of Dhama, "All Phenomena Lack Self-Existence"