When Sod Is Peshat

The end of the parsha is quite cryptic.  The whole episode of Avrohom marring Keturah and the children they had.  Who is she, why did Avrohom marry her, why do we need to know about them, why did Avrohom give them an inheritance of a shem tumah?  All of these questions are difficult and have been addresed from Chazal downward but it still is very difficult.  The Gemorah says (Zevachim 62b) that the nephews of Rav Tarfon were sitting with him and no one was saying anything.  So he said ויוסף אברהם ויקח אשה ושמה יוחני.  They said the possuk doesn't say יוחני, it says קטורה, so Rav Tarfon called them bnei keturah (Rashi explains that they don't know how to learn.)  Obviously, this Gemorah needs explanation, why did Rav Tarfon read the possuk wrong, why was that a way of expressing the ignorance of those around him?  Rav Schwab quotes Morenu Rav Yaakov Rosenheim (see here) in the name of a gadol that we understand the nigleh of Torah via the three lower dimensions of the neshama which are nefesh, ruach and neshama.  Similarly the depths of Torah, the nistar, can be understood (by those that know) via three dimensions and they are chayeh, yechidah and nefesh yeserah.  He said that this parsha can only be understood in the light of pnemious hatorah.  That is what Rav Tarfon was saying, יוחני stands for yechedah, v'chayeh, nefesh yeserah.  Rav Tarfon thought maybe his nephew's weren't discussing halacha or briskor lomdus because they were kabbalists and were quietly pondering their kabbalistic thoughts.  Therefore, Rav Tarfon was hinting to them the process of understanding the depths of Torah so they can discuss those thoughts instead of just thinking.  However, they didn't get the hint and Rav Tarfon derived they were just ameh ha'aretz.  Rav Shwab seems to be acknowledging there are aspects of Torah that could only be understood based upon pnemious hatorah, which is an opinion the Lubavatcher Rebbe advanced as well.  I am just surprised that a yeki would say the same thing.
A simple lesson from the whole episode is reflective of what  this blog says here that even as Avrohom grew older he was still active and sought to raise more children.