Be A Baby

The constellation of Elul is betulah.  Why is that the motto of Elul?
The Gemorah say that when רבי אלעזר בן דורדיא was repenting he put his head between his knees and then processed to meditate on his life.  Why did he place himself in such an uncomfortable, strange position?
In the past, we discussed the 40 days from Elul to Yom Kippur correspond to the 40 days that it takes an embryo to form.  The ultimate teshuva is form a person to clean off his/her soul to reach the level of purity as they were in while in their mother's womb.  The same stance that רבי אלעזר בן דורדיא was in is how the Gemorah in Niddah (30b) describes the appearance of a fetus in its mother's womb, וראשו מונח לו בין ברכיו.  Rebbe Eliezer ben Dordayah was able to cleanse his soul to the level of  purity that it was at in it s mother womb. 
The Sfas Emes Elul (5647-8) says the message of the betulah is that there is a inner spark of purity that has not become defiled no matter how much on has sinned, "והנה מזל אלול בתולה. היינו שיש נקודה פנימית בנפש ישראל שאין שולט שם מגע נכרי. גן נעול. מעיין חתום. ונק' בתולה וע"ז הנקודה נאמר אני לדודי שלעולם לא נתרחקה זו הנקודה מדביקות בשורשה. ושמורה לשמו ית."  That is the 40 day journey that starts from the beginning of Elul.  We are going trough an intensive cleansing process to remove the grime and dirt covering the soul to reach the inner spark, that part of the soul that is as pure as it was before entering the dangerous world. It takes 40 days to reach the first day of the forming of the embryo, that is the spark that remains uncontaminated.  This is a unique process that the aid for it comes during this time as the Sfas Emes continues: אך לא בכל עת יכולין למצוא זו הנקודה. ועתה הזמן גורם שנתעוררו בנ"י בתשובה. ונתקרבו נפשות בנ"י אליו ית.