Bubbyo: My reply reflects my Bais Yaakov background, there are probably other responses as well.
As a follow-up: What benefit accrues to the deceased by gaining more merit?
“he/she, in the world of truth, will delight in this added bit of awareness that resulted from their life..,this will elevate the soul and thus alleviate some of the pain”
Thanks Bubbyo for your very interesting response.
The reason I posed this question to the forum is to demonstrate that those on earth can affect the deceased. It is reasonable then to conclude the deceased can affect those on earth and hence, can affect where a person turns a page to a particular igros.
Your explanation apparently leaves Hashem entirely out of the path between living an deceased. By adding Hashem into the “model”, Kaddish affects the deceased through Hashem. The Kaddish moves Hashem to ease the cleansing of the soul of the deceased.
Unless someone wants to argue that this is a “one-way street” , the deceased can affect the living through Hashem. Hence, a holy soul (eg., Metatron like?) can influence Hashem to act in the world. This is a reasonable mechanism that can explain the selection of the appropriate igros as well as other actions and “miracles” we observe.
I spoke to my Chabad Rabbi a bit more about the difference between selecting an igros at random and studying the works of the Rebbe. He remarked that by consulting a volume of letters one will pick out the answer that leads to one’s desires. When “randomly” selecting, one can get an answer they did not want and hence will prevent them from doing that which they desire.