91 Come! This long-desired unity, fostered and fed by brotherly love, will beget a great peace. This is the peace "which surpasses all understanding," (42) since its birthplace is in heaven. It is the same peace which Christ promised to men of good will through the song of the angels who hovered over His crib; (43) it is the peace He imparted after instituting the Eucharistic Sacrament and Sacrifice: "Peace I leave with you, my peace I give to you; not as the world gives do I give to you." (44)
Source: Ad Petri Cathedram (Vatican.va)