Verse Ex17-12c discussing Moses' prayers
for t he Jewish people during the war with Amalayk
But Moses’ hands were heavy; and they took a stone, and put it under him, and he sat on it; and Aaron and Hur stayed up his hands, the one on the one side, and the other on the other side; and his hands were steady until the going do
The rules of symbolism,
listed in the above article, require symbolic
interpretation when a verse description is anomolous.
Here Moses supporting his hand with a stone
versus a pillow is anomolous.
The rules of symbolism, listed in the
state that when symbolic interpretation is required,
we interpret items by function, form, linguistic
association, and Biblical assocaition. In this
case Rashi uses the form of resting on a stone:
Resting on a stone is painful. Moses abstained
from resting on a pillow to symbolically affirm that
he empathized with the suffering of the Jewish people.
This empathy was a source of strength to them and
encouraged their fighting. Even though Moses was an
angel and did not need war he emphasized his empathy
with the plight of the Jewish people.