邂逅わくらば

nari-adjective (archaic / formal)

by chance; coincidental; occasional; rare

Archaic adjective (nari-form) meaning something happening by chance or being rare. Not used in modern Japanese; found only in classical texts.

• 邂逅わくらばの出で会あいは、古ふるい物もの語がたりによく描えがかれる。

  Chance encounters are often depicted in old tales.