Dan's Darkness

It is noted by holy books that the name of Hashem (in the יקוק form) does not appear in the parshios of Mikatz, Vayigash and the beginning of Vayechi.  Why is that?  And why does it finally appear in the possuk לישועתך קויתי ה?  And why is this prayer amended to the beracha of the tribe of Dan?  

The shevet of Dan is associated with the month of Teves.  What is the connection?  Chazal refer to ח, ט, י טבת as the three days of darkness.  The tribe of Dan is associated with those consumed with an inner darkness.  It is the tribe of Dan that brings along the פסל מיכה through the Yam Suf.  They are the rear guard of the tribes in the desert.  The ones holding up the rear spiritually.  

The darkness of the days of Teves is due to the fact that Teves is under the auspices of Esau.  It order to counteract this power it is necessary to have a tribe from Klal Yisrael that is associated with darkness but is able to transform this darkness into light.  That is the tribe of Dan.  As the Mictav M' Eliyahu (volume 2) elaborates on in his piece about Shimshon, see 'Shimshon the Messiah'. As Rav Dessler notes, in the beracha of Moshe, Dan is also compared to a lion in the same vein as Yehuda, דן גור אריה.  His kingship, his Messianic potential is due to his ability to steep into the dark forces and elevate them.  גור אריה יהודה, the essence of Yehuda is to rule, to be a lion but Dan first is Dan, has to associate with the lowness of life and then can elevate that to גור אריה.  

As explained in various sefarim, the name of Hashem is missing through the parshios of the descent of Klal Yisrael into the golus of Egypt.  In the golus the open hand of Hashem is no longer recognized.  It is a time of darkness.  It is in this time that the light of the tribe of Dan is able to illuminate some of the darkness by finding Hashem within the bleakness.  When Yaakov sees this middah present in the tribe of Dan, he evokes the name of Hashem.  Rashi says this is a prophecy about Shimson after he is captured.  Even when there is no more hope, he still is able to bring back a taste of the light.  

The Ramchal in מאמר הקיווי (available online) says the root of the word  קויתי is the word קו, a line, a reference to the Kabbilistic explanation of the construct of the world in which there is a concealment and then the light is brought back starting by a ray, a line of light.  In it this ray of light that Dan connects to.  Even in the bleakness of golus of Teves, he is able to find the ray of light to illiminate the darkness.