应该是指禅宗吧！Zen Buddhism Zen is a school of Mahāyāna Buddhism（大乘佛教）, translated from the Chinese word 禅 Chán to Japanese. Zen emphasizes experiential prajñā, particularly as realized in the form of meditation, in the attainment of enlightenment. As such, it de-emphasizes theoretical knowledge in favor of direct, experiential realization through meditation and dharma practice.

参考资料:
http://en.wikipedia.org/wiki/Zen

I'm guessing it has to do with meditation, or meditative teachings.