23 Consider again that sacred ministers do not renounce marriage solely on account of their apostolic ministry, but also by reason of their service at the altar. For, if even the priests of the Old Testament had to abstain from the use of marriage during the period of their service in the Temple, for fear of being declared impure by the Law just as other men, is it not much more fitting that the ministers of Jesus Christ, who offer every day the Eucharistic Sacrifice, possess perfect chastity? St. Peter Damian, exhorting priests to perfect continence, asks: "If Our Redeemer so loved the flower of unimpaired modesty that not only was He born from a virginal womb, but was also cared for by a virgin nurse even when He was still an infant crying in the cradle, by whom, I ask, does He wish His body to be handled now that He reigns, limitless, in heaven?"
Source: Sacra Virginitas (Vatican.va)