勸發菩提心集 3.109

3.109

忍九門者：一、自性者，或思擇力，或由自性，堪忍怨害，由無染心，純悲愍故。能有堪忍，此名自性。

The nine portals of forbearance (kṣānti): First, intrinsic nature (svabhāva): through the power of reflection or by one's own nature, one endures injury from enemies because of an undefiled mind and pure compassion. Being able to have forbearance is called its intrinsic nature.