Catechism of the Catholic Church

"All priests, who are constituted in the order of priesthood by the sacrament of Order, are bound together by an intimate sacramental brotherhood, but in a special way they form one priestly body in the diocese to which they are attached under their own bishop...." The unity of the presbyterium finds liturgical expression in the custom of the presbyters' imposing hands, after the bishop, during the rite of ordination. (1537)