Upāya / Expediency
This concept refers to appropriate skilful means or methods. “Expediency” is often used together with “ingenuity” (kauśalya). It refers to the Buddha’s or to a bodhisattva’s preaching adapting to the circumstances, in order to convert beings. He used adroit words and terms and narrative techniques, so as to allow listeners of different backgrounds all understand and comprehend it and grasp the implied abstruse meaning. The concept of “expediency” is a key to the Great Vehicle (Mahāyāna) sect of Buddhism. It emphasizes that all verbal expressions, including the Buddha’s teaching, depend on the concept of the term and appearance. They cannot obtain the highest level. In a certain sense they are all expedient means, like a finger pointing at the moon. That is why they should not be literally interpreted. One should not cling to them.
Since I have become Buddha, I have widely developed and verbally taught several kinds of causality stories and several kinds of similes. With countless skilful means I have guided the beings, so that they would abandon any attachment. (Scriptural Text: The Lotus Sūtra of the Wonderful Dharma)