Koan in Chinese / Japanese...

In Buddhist context, this is a Zen question for meditation.

From the Buddhist dictionary this is:
Problems set by Zen masters, upon which thought is concentrated as a means to attain inner unity and illumination.

The secular meaning of this word can mean a judge's desk, complex legal case, contentious issue, a dossier, case record, public laws, regulations, or case-law.

This controversial Buddhist koan means, "On encountering Buddha, you should kill him".

This is the short concise Japanese version of an original statement by ninth-century Chinese Buddhist monk Linji Yixuan, "If You Meet The Buddha On The Road, Kill Him".

This takes some explaining... The concept here is that if you think you have seen, experienced, or achieved true enlightenment, the chances that you really have are so slim that you should kill or dismiss that idea.

Another suggestion is that one's path to becoming a Buddha is one's own, and one should not get caught up in religious fervor, and avoid "showing off" that they are a Buddhist.

Helpful references for this concept:
Lion's Roar addresses "If You Meet The Buddha On The Road, Kill Him"
Kill the Buddha

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.