四分戒本疏卷第一．第二．第三 3.17

3.17

The eighth precept: speaking of one's actual attainment of the path to an unordained person.
The treatises say that it was instituted for two reasons: First, for the sake of the practice of great beings. It is proper in principle to conceal merit and expose offenses. To now speak of one's own virtuous conduct while hiding one's faults is not the practice of great beings. Second, by displaying one's noble virtues oneself, a distinction is drawn between the worthy and the foolish; when the other person hears of it, their mind becomes partial and devoted [only to that individual], losing the equal, pure, and wholesome mind. Therefore the Sage instituted it.
There are five specific conditions: 1. having actual virtues within—[this condition] excludes those with excessive pride, [and if] the object is unreal, there is no offense; 2. stating them to be one's own; 3. speaking to an unordained person; 4. clear speech; 5. the other person hearing and understanding. Moreover, this precept has no separate origin story; it was formulated based on the [formulation of the rule against] grave false speech, where some had actually attained [the states]. Once instituted by the Sage, no noble being ever violated it again; this means it was instituted to guide the noble and prevent ordinary persons [from doing so].