40 Further, it is by no means futile to observe that in the East only celibate priests are ordained bishops, and priests themselves cannot contract marriage after their ordination to the priesthood. This indicates that these venerable Churches also possess to a certain extent the principle of a celibate priesthood and even of the appropriateness of celibacy for the Christian priesthood, of which the bishops possess the summit and fullness. (81)
Source: Sacerdotalis Caelibatus (Vatican.va)