The Heart Sutra is considered the most profound, the essence of the Buddha’s teachings. It is considered the most supreme of all teachings. Buddha cannot bear to see sentient beings suffer and wants to free them from samsara. He cannot rescue them from their negative deeds. He can only show them the path he has taken.
What leads to liberation? Only by understanding and meditating on emptiness. Since it presents the path, the complete framework, that is why the Heart Sutra is the supreme teaching.
The Buddha did not teach those who are not matured enough or those who are not interested in emptiness. If a person’s primary interest is in this life, there is no need for emptiness. It is not relevant to him. It is relevant to those who think more deeply and go beyond the 5 senses. On a deeper level, as long as you are influenced by mental affliction and karma, if you do not do something about it, then it continues forever. Then emptiness becomes an important subject. Emptiness is the gateway to liberation, to subdue one’s mental afflictions.
— 4th Zong Rinpoche, Tenzin Wangdak