mayamevamhā alakkhikā mayaṃ appapuññā te mayaṃ evaṃ svākkhāte dhammavinaye pabbajitvā nāsakkhimhā yāvajīvaṃ paripuṇṇaṃ parisuddhaṃ brahmacariyaṃ caritu’’nti
We were unlucky, we have little merit; for though we went forth into homelessness in such a well-proclaimed Dhamma, we were unable to live the perfect and pure holy life for the rest of our lives.
eg MN 77
It's not clear from the suttas or the Vinaya what the Buddha or the redactors themselves thought about this sob-sob reaction, but it's quite clear from the texts that the speakers believe what they said about lacking the supporting conditions for success in the monastic life. Not quite "grace" in the theistic sense of from "another", but what are we anyway if not the product of "our" past?