I’ve noticed that preaching in Europe – in French Reformed churches, Anglican churches and Romanist churches – ends with the word ‘Amen’; at Westminster, it was also preceded by something like ‘may that which I proclaim be the word of the Lord’. Although this doesn’t really make the preaching better, it does remind everyone what a serious task preaching is and what position it takes in the service: it helps people to resist ‘sharing a message’ rather than proclaiming the message that already is in the portion of Scripture appointed to be read.
For Jesus was teaching the Israelites as one with authority, not like their scribes. A result of his kenosis (emptying) is that he chooses to work through his mystical body, the Church. His authority, all the authority in heaven and on earth which has been given to him, is invested into his Church to proclaim the Word and to scatter abroad his gifts to the poor in spirit. God’s stance vis-à-vis the world, and thus the Church’s stance, cannot be of one who shares thoughts: it must be of one who declares that which is upon the authority of the Maker himself.