Siddhartha Gautam, aka Sakyamuni (the sage of the Sakyas), became a buddha around 2,500 years ago. Today, known as Buddha Purnima, the day of the full moon in May, is celebrated as his birthday. Here’s the Chinese singer Imee Ooi singing the Prajna Paramita Hridaya Sutra, aka The Heart Sutra. Listen.
The maha-mantra of the Heart Sutra, “om gate, gate, para-gate, parasum-gate, bodhi svaha om”, appears around the 3:50 time stamp.
About the Heart Sutra, Wikepedia says:
Briefly the sutra introduces the bodhisattva of compassion, Avalokiteśvara, who in this case is representing the faculty of prajña (wisdom). His analysis of phenomena is that there is nothing which lies outside the five aggregates of human existence (skandhas) — form (rūpa), feeling (vedanā), volitions (samskārā), perceptions (samjñā), and consciousness (vijñāna).
Avalokiteśvara then addresses Śariputra, who in this text — as with many other Mahāyāna texts — is a representative of the Early Buddhist schools, described in many other sutras as being the Buddha’s foremost disciple in wisdom. Avalokiteśvara famously states that, “form is emptiness (Śūnyatā) and emptiness is form” and declares the other skandhas to be equally empty — that is, without an independent essence. Avalokiteśvara then goes through some of the most fundamental Buddhist teachings such as the Four Noble Truths and explains that in emptiness none of these labels apply. This is traditionally interpreted as saying that Buddhist teachings, while accurate descriptions of conventional truth, are mere statements about reality — they are not reality itself — and that they are therefore not applicable to the ultimate truth that is by definition beyond dualistic description. Thus the bodhisattva, as the archetypal Mahāyāna Buddhist, relies on the perfection of wisdom, defined in the larger Perfection of Wisdom sutras to be the wisdom that perceives reality directly without conceptual attachment. This perfection of wisdom is condensed in the mantra with which the Sutra concludes.
See also the “Form is Emptiness” post from May 2007 in which I have the full text of the Prajna Paramita Hridaya Sutra.