http://revach.net/article.php?id=4180

Section: Parshas HaShavua   Category: Life Lessons
Parshas Vayeitzei: Rav Chaim Zaitchek - When Hashem Spoke To Yaakov, He Turned Out The Lights
The medrash says that the reason why the sun set early when Hashem spoke to Yaakov on his way to Charan was because Hashem wanted to speak to him privately so he turned off the lights.  Rav Chaim Zaitchek, a Talmid of the Alter of Novhardok in Ohr Chadash asks, does Hashem need the dark to have privacy with Tzaddikim?  Can He not have a private moment in broad daylight?

He answers with Rav Yaakov Emden who says that everything Hashem created in this world is a cover to His true glory.  Hashem is the ultimate good and the ultimate bright light, kviyachol.  Even the mighty sun with its brilliant light is cover for the true eternal light.  So are the Malachim.  Hashem wanted to speak to Yaakov directly with no interference.  He ripped open the sky and revealed to Yaakov the true light from above.  For this Hashem needed to extinguish even the sun.

Rav Chaim Zaitchek concludes that for us to see the true light of Hashem we must also be willing to extinguish all the bright lights of Olam HaZeh.  Only then will Hashem reveal to us, privately, the brilliant eternal light.