Read the assigned scripture.
Read the scripture surrounding the assigned scripture.
What is being communicated?
How is it being communicated?
How does it fit into God's story of Creation, Fall, Redemption, and Restoration?
How is it pointing to Christ?
What issues is it speaking to?
How is it challenging you?
These questions shouldn't be mere inquiries into the text, as if you were interrogating it--or hunting for answers. Rather, they should be integrated into the preacher's approach to the text. All scriptural texts point to Christ. All scriptural texts exist in God's redemptive story. Listening to the text involves hearing the text's response to the questions.
Further, these questions shouldn't be asked as if you were above the text, analyzing it. They should be reverently asked, as if you were below the text.
The temptation is to ask only "How can I use this text to teach?" The preacher must begin with "What is the text saying." To start with "How can I use this text" short-circuits the process of listening to the text. Ask the Spirit to confront you through the text. Ask the Spirit to pierce your heart. Ask the Spirit to hear the challenging word, before saying the challenging word. This will revive your soul and will later be the 'raw material' of the sermon.
Take your time.
Listening takes patience.
You may think you have an 'answer'--don't move too quickly.
Listening is an act of prayer.