on such foundations, then though heavy storms of passions break over it, though mighty torrents of persecutions beat against it like a battering ram, though a furious tempest of spiritual foes dash against it and attack it, yet not only will no ruin overtake it, but the onslaught will not injure it even in the slightest degree.
Complete source paragraph · Conferences of John Cassian, Part I, Chapter II.; original source section: Chapter 2; original book/conference: IX. The First Conference of Abbot Isaac., source paragraph 4 · Original source