The brazen altar of the old Testament was constructed with 4 raised corners, or horns. To each corner was attached a cord and thus there were 4 bands with which to bind the sacrificial victim. According to Ann Catherine Emmerich, Jesus was bound by four ropes when led out of the Garden.
We may think of this as the priest walks to the Epistle side of the altar. Knowing that the priest is about to commence the great unbloody Sacrifice, we can continue to prepare for interior participation by praying thus:
“Lord Jesus Christ, who wouldst be bound by the hands of wicked men; loosen, I beseech Thee, the chains of my sins, and so tie me with the bands of charity and cords of Thy commandments, that I may neither in thought, word, nor deed, hereafter offend Thee. Amen.”
In the N. O. the priest stands by his presider’s chair while a server comes to him with the missal.