Gregory of Nyssa, on Song 4:12

“My sister, my spouse, is a garden enclosed, a garden enclosed, a fountain sealed up.”

“Because a seal protects the inviolability of whatever it guards, it scares off thieves; everything not stolen remains unharmed for the master. Praise of the bride in the Song would then testify to her excellence in virtue because her mind remains safe from enemies and is guarded for her Lord in purity and tranquility. Purity seals this fountain while the radiance and transparency of the bride's heart is unclouded by no mire of evil thoughts.”

Imported from an open dataset — not yet checked against the printed edition.