Zazen shin (), rendered in English as the Acupuncture Needle of Zazen, Lancet of Zazen, or Needle for Zazen, is a book belonging to the Shà Âbà Âgenzà  (æ£æ³Âç¼èµ, lit. "Treasury of the True Dharma Eye"), the collection of works written in Japan by the 13th century Buddhist monk and founder of the Sà Âtà  Zen school, Eihei Dà Âgen. It was written on the 19th of April, 1242 at Dà Âgen's monastery Kà Âshà Âhà Ârin-ji in Kyoto. The book appears as the 12th book in the 75 fascicle version of the Shà Âbà Âgenzà Â, and it is ordered 27th in the later chronological 95 fascicle Honzan editions. The title Zazen shin refers to a poem of the same title written by Hongzhi Zhengjue. Hongzhi's poem is quoted verbatim in Dà Âgen's Zazen shin and also presented again in modified form later in the text.
The Zazen shin lays what Dà Âgen sees as the vital importance of Zazen (Japanese: Ã¥ÂÂ禠, lit. âÂÂSitting meditationâÂÂ) to his school of Buddhism. Dà Âgen emphasises in Zazen shin that Zazen is not a way to become the Buddha, but rather a practice used by the enlightened to focus on the present. Rather than being seen as a way to become enlightened, he argues that it is something that the enlightened do. Later in the text Dà Âgen comments on the story of Chan master Mazu Daoyi who likened trying to become a Buddha through meditation with polishing clay tile to make a mirror, something which is impossible and does not make sense. The final part of the work is Dà Âgen's commentary on Hongzhi Zhengjue's poem, and Dà Âgens own version of that poem.