I think Soma is either the Aminita Muscaria mushrooms that people think.
OR
TONS of plants contain DMT. India has big "Evil Eye" tradition. And one plant that is good for removing evil eye is Syrian Rue (An MAOI). Which means a lot of them proobably had that, considering it grows there. And it was important in some groups there.
they said it may have been squeezed from a plant, it was treated sacred on some god shit, then it was used casually so it lost its sacred value and became a problem so they retained the experience and stopped using the drug so knowledge of what it actually was is lost over the years?!!
Damn, I posted a long answer to this but it isn't here. SOMA is possibly blue lotus. The pharma SOMA is interesting however, it metabolizes to meprobamate which was the first tranquilizer and very popular. Huxley incorporated such a substance in Brave New World called SOMA where everyone takes grams of the stuff to fight depression.