The Platform Sutra of the Sixth Patriarch (Liu Tsu T'an Ching) is a Buddhist scripture that was composed in China in the late seventh century. It is one of the most important texts in the Zen school of Buddhism.
A considerable amount is known about Hui-neng, although some scholars have questioned whether he actually wrote the Platform Sutra and have attributed the work to a later publisher Shen-hui (668-760). The question becomes whether Shen-hui copied Hui-neng’s words or made them up himself and attributed them to the teacher.
According to tradition, Hui-neng was born in 638 in Canton into a poor, family. His father died when he was young and he was forced to work from a young age and as a result he did not have the chance to learn to read or write. One day, while he was delivering firewood to an inn, he heard a guest reciting the Buddhist “Diamond Sutra” and he had an awakening. He immediately decided to seek the Way of Buddhahood. The guest gave him money to provide for his mother, and Hui-neng embarked on a journey northward in search of enlightenment.
After traveling for 30 days, Hui-neng arrived at Huang Mei Mountain, where the Fifth Patriarch Hon-gren presided. He asked Hui-neng where he was from and what he sought. Hui-neng replied that he was seeking Buddhahood.
Hon-gren told Hui-neng that barbarians were from the south, so it would be difficult for him to achieve Buddhahood. But Hui-neng famously replied by saying that people may come from north or south, but the Buddha nature has no north or south.
Hui-neng entered the monastry and began studies. One day Hon-gren suggested the next Patriarch be picked from the person who understood the true nature of dharma and the essence of mind and who could write a poem explaining it. Everyone assumed the learned Shen-xiu would win easily. But Hon-gren did not accept his poem. Hui-neng, then an unassuming rice pounding novice, spoke up with his poem, which captured the essence of mind perfectly according to Hon-gren who conferred the title of Sixth Patriarch upon Hui-neng.

The Platform Sutra of the Sixth Patriarch

The Sutra is a relatively short set of instructions to the disciples of the Patriarch. It is regarded as one of the cornerstone texts of Zen Buddhism. Traditionally, The Sutra was preached by the Sixth Patriarch of the Ch’an School, Hui-neng, at the Shao Zhou temple.
In The Platform Sutra, Hui Neng instructs his disciples on his Final Instructions, "After my entering Nirvana, each of you will be the Dhyana Master of a certain district. I am, therefore, going to give you some hints on preaching, so that you may keep up the tradition of our School."
The key topic of the Sutra is “sudden” enlightenment, the direct perception of one’s true nature, and the unity  of dhyana (meditation), sila (morality or ethics) and pranja (wisdom). Southern Ch’an or "Sudden Enlightenment" school of Ch’an Buddhism based its doctrine on this extremely influential scripture.