It's true that prayer often features as a perfunctory step in the process, even as an act of desperation as Sunday morning approaches. But we all know that payer ought to be a central feature not a peripheral part of the process. As the author of the post says:
We need to regain a theological vision in which prayer becomes the posture of the preacher, for before our people can hear from God through us, we must hear from God ourselves. And hearing from God through his Word is the fundamental work of prayer.
But not only is prayer about hearing from God, it is also about something more fundamental too:
The point of prayer is realignment, as our hearts assume a posture of dependence and humility before God. Prayer places our needs in the perspective of God's sufficiency, our problems in the perspective of his sovereignty, and our desires in the perspective of his will. Prayer is not a monologue. Rather, prayer invites God to have the last word with us, and for his Word to shape and define us.
This is true whether you are praying as you prepare to preach or whether you are praying as you prepare to live out your daily life for the glory and honour of God.