No commandment?
Well, Jesus’ words should count for something.
“For some are eunuchs because they were born that way; others were made that way by men; and others have renounced marriage because of the kingdom of heaven. The one who can accept this should accept it.”
Well obviously some priests can’t accept it. Did Jesus renounce them? No. Did He declare them unfit for Heaven? No. Did He declare them unfit to preach the Gospel? No. Did He put any restraints upon their authority, duties or fitness to serve? No.
If a priest has come so far as to reason himself to marriage, then he should probably reason himself out of your church.