Following are my Divrei Tora from Parashat Bo:

• Dvar Tora from Shabbat Bo, 5774: “The Mixed Multitude: Fellow Travelers or Bad Influence?”
• Another Dvar Tora from Shabbat Bo, 5774: “In the Dark”
• Dvar Tora from Shabbat Bo, 5771: “Pharoah Looks for a Blessing”
• Dvar Tora from Shabbat Bo, 5770: “Haiti and Theodicy”
• Dvar Tora from Shabbat Bo, 5769: “Making the Invisible Visible”
• Dvar Tora from Shabbat Bo, 5767: “The mechanisms of the plagues” (mp3 audio)
• Dvar Tora from Shabbat Bo, 5765: “Does It Take a Miracle to See a Former Enemy in a Favorable Light?”
• Dvar Tora from Shabbat Bo, 5764: “Pharoah Looks for a Blessing”

Note: Some of these essays have been updated over the years. Even when the same title appears, editing and changes have been applied and the essay has been somewhat altered. You might want to look at only the latest iteration of the essay. On the other hand, particularly if you have difficulty with a particular idea, checking earlier versions may be helpful.