一樹の陰一河の流れも他生の縁
Meanings
1
everything is preordained; nothing happens by chance
A Buddhist proverb meaning that even the smallest encounters are the result of karma from past lives; often used to express that meetings and events are not coincidental.
As the saying goes, 'Even the shade of a single tree and the flow of a single river are due to karma from a previous life,' so every encounter must have meaning.