大乘起信論廣釋卷第三．四．五 5.127

5.127

論。是故眾生至不應誹謗　釋曰。此誡勸止謗也。毀謗獲大罪故。經不發三惠善根。但可仰信不應謗也。

Treatise: "Therefore, sentient beings … ought not to slander it." / Commentary: This is the admonition and exhortation to cease slandering. Because slandering incurs great transgression, even if through the sūtra one does not generate the wholesome roots of the three wisdoms, one should simply revere it with faith and ought not to slander it.