Gregory the Dialogist : What but the holy Church is figured by the ark? To which four rings of gold in the four corners are ordered to be adjoined, because, in that it is thus extended towards the four quarters of the globe, it is declared undoubtedly to be equipped for journeying with the four books of the holy Gospel. And staves of shittim-wood are made, and are put through the same rings for carrying, because strong and persevering teachers, as incorruptible pieces of timber, are to be sought for, who by cleaving ever to instruction out of the sacred volumes may declare the unity of the holy Church, and, as it were, carry the ark by being let into its rings. For indeed to carry the ark by means of staves is through preaching to bring the holy Church before the rude minds of unbelievers by means of good teachers. And these are also ordered to be overlaid with gold, that, while they are resonant to others in discourse, they may also themselves glitter in the splendour of their lives. Of whom it is further filly added, "They shall always be in the rings, nor shall they ever be drawn out from them;" because it is surely necessary that those who attend upon the office of preaching should not recede from the study of sacred lore. — The Book of Pastoral Rule, Part 2, Chapter 11