preface (something) with (doing something)
To recite something as an introduction to something else. Often used in passive constructions. Let me preface this statement with an unreserved apology for what has happened. We should always preface these board meetings with a reading of the previous meeting's minutes.
preface something with something
to begin something with a particular message. She prefaced her speech with a recitation of one of her favorite poems. Alice prefaced her remarks with a few personal comments.