An excerpt from the third book of the Rationale Divinorum Officiorum of William Durandus of Mende, Englished by T.H. Passmore:
1. Now the Albe must be girded around the loins of the Priest or Bishop with a Zone or Girdle, called in the Law and by the Greeks balteus, lest it flow down and hinder his steps; that no motives may provoke him to relax his chasteness, whereof the Albe is a type. For the Girdle doth signify continence, as it is written, LET YOUR LOINS BE GIRDED ABOUT, AND YOUR LAMPS BURNING IN YOUR HANDS; for that in the loins lust reigneth, as the Lord sheweth, speaking of the devil, HIS STRENGTH IS IN HIS LOINS, AND HIS FORCE IS IN THE NAVEL OF HIS BELLY.
2. On the left side of the Bishop there hangeth down from the Girdle a two-fold Undergirdle, because there be two things whereby Chastity is made strong, and without which it is hardly preserved, to wit, Prayer and Fasting. Thus the Lord saith, THIS KIND GOETH NOT OUT, BUT BY PRAYER AND FASTING.
3. With Continence, therefore, ought the loins to be girded, and under-girded with Abstinence; wherefore the Apostle, STAND HAVING YOUR LOINS GIRT ABOUT WITH TRUTH. But the Undergirdle, which is called otherwise Perizona or Succingulum, was not found among the Vestments of the Law. For though the Priests of the Law, being girded, must not come at their wives in the time of sacrifice, yet at other times they were free in this matter. But nowadays one girdle is added, for the ministers of to-day must needs have continence, and therefore they must be not only girded, but also under-girded.
4. Wherefore the Undergirdle is twofold, to denote a two-fold chastity: namely, of the mind, as the Girdle, and of the body, as the Undergirdle signifieth. And this latter hangeth, as I have said, from the left side; for as the right is mightier than the left, so is chastity of mind more potent than chastity of body. Wherefore Saint Gregory saith, 'We gird our loins, when we restrain the lust of the flesh through continence.
5. The Girdle doth also fitly designate temperance. (Of the Undergirdle I have spoken also in the Proeme of this Book.) And mark that (as hath been already said) the breast and throat are but loosely held bound by the Amice, because their motions are not under our power. Elias did sooner shut up heaven when he prayed that it might not rain, than his own wrath, when he desired vengeance for the death of the prophets. The tongue, too, dwelleth in moisture and dampness, and is made easily to slip, even as the Prince of the Apostles did at the word of a damsel deny his Master. But by the Girdle the reins are bound strongly and tightly, that we may buffet the body and bring it into servitude, and may bridle the motions of lust.
6. As touching that which agreeth unto the Head, even Christ, the priestly Girdle is a figure of that whereof the Apostle John speaketh: AND I TURNED, AND SAW ONE LIKE UNTO THE SON OF MAN, GIRT ABOUT THE PAPS WITH A GOLDEN GIRDLE. By a 'golden girdle' is intended the perfect love of Christ, called by the Apostle the LOVE OF CHRIST WHICH PASSETH KNOWLEDGE, burning within the heart, and shining forth in works. And its Undergirdle doth represent that which Esaias did prophecy, speaking of Christ, AND RIGHTEOUSNESS SHALL BE THE GIRDLE OF HIS LOINS, AND FAITHFULNESS THE GIRDLE OF HIS REINS. For again, THE RIGHTEOUS LORD LOVETH RIGHTEOUSNESS: HIS COUNTENANCE WILL BEHOLD THE THING THAT IS JUST. And, THE LORD IS RIGHTEOUS IN ALL HIS WORKS. The two ends of it are the two natural precepts of the righteousness which Christ wrought and taught, to wit, 'Do not unto others as ye would not have them do unto you, but as ye would that men should do unto you, do ye also unto them.' It doth therefore represent Righteousness, having two arms joined tightly together, that is, to refuse evil and to do good.
The Girdle signifieth also the scourge, with which Pilate did scourge Jesus.