To me, two facts point to the physicality of their bodies:
1. They needed to eat.
“See, I have given you
every herb that yields seed which is on the face of all the earth, and
every tree whose fruit yields seed;
to you it shall be for food..." Genesis 1:29 NKJV
Pre-fallen Man
had to eat, but supply easily kept up with demand (until the ground was cursed in Genesis 3:17-19).
2. They were expected to make babies.
“Be fruitful and multiply; fill the earth and subdue it;..." Genesis 1:28 NKJV
Ethereal souls cannot do that.
What is telling is that they were commissioned to do so
before the Fall, but Eve's first conception took place
AFTER the Fall. That strongly suggests that they fell before Eve's
first ovulation. (That would be about a month by today's standards.)