釋禪波羅蜜次第法門 1.52

1.52

共名者，如禪一字，凡夫、外道、二乘、菩薩、諸佛所得禪定，通得名禪，故名為共。

As for the shared name: the single character *chan* (dhyāna) can generally be applied to the dhyāna-concentrations attained by ordinary persons, non-Buddhists, followers of the two vehicles, bodhisattvas, and all Buddhas; hence it is called shared.