Here’s a random cultural fact about Japanese and Zen. In Japanese, the word commonly used for “greeting” is aisatsu (挨拶). However, a while back, I read in my cultural guidebook, that the word was originally used in Zen Buddhism to describe when two monks met one another, and tested each other on their knowledge of the moral precepts and other aspects of Buddhism. It helped the two monks establish who was the elder (the wiser, more experienced monk) and the junior, I believe.
Now though, the term means anytime you meet someone and exchange greetings. It’s another example of Buddhist terms that become everyday Japanese. :)
Something I wanted to pass along. :)