On Modesty:

But let thine apparel be plain, not for adornment, but for necessary covering: not to minister to thy vanity, but to keep thee warm in winter, and to hide the unseemliness of the body: lest under the pretense of hiding the unseemliness, thou fall under another kind of unseemliness by thy extravagant dress.

St. Cyril of Jerusalem, Catechetical Lectures (IV)

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Even devils in their craftiness and beastly manners and with their arrogant minds; they become like dust when they face a modest person.

St. Isaac the Syrian