He was placed in a tube like structure, though; especially if you have reviewed the way Jewish tombs were constructed.
OTOH:
Bowls is the word for “womb” or “tummy”; as in mommy has a baby in her tummy; but it’s more than just idiom – it’s also a view of generally understood ancient science.
The intestines of a woman or man were similar enough to the uterine tubing of a woman, that the ancients thought them equivalent in their operation (not their media).
Also, there was a relationship between how the ancients understood agriculture and how they saw sexual reproduction; although there are varying views…
In a simplistic way: Both vegetative and sexual reproduction have a furrow that is plowed, and a seed that is placed in a pit or trench, and the pit or trench contains elements (earth,water,hopefully air) from which something grew. Whether a child, or a plant… was incidental.
IF you study the ancients, you’ll quickly find that the elements were “earth, water, wind, fire”.
So:
When Jonah was in the sea beast/fish/whale – the prophecy says;“in the coils” (bowels --not just the stomach); and Jonah calls it the gates of sheol (the grave), and the pit (an allusion to where water collects, like a womb.)
So, in some ways – it’s actually more surprising that Jesus would be called “firstborn” from the dead, when Jonas is usually understood to be the child whom Elijah resurrected from the dead … and who resurrected a second time in the womb equivalent called leviathan… after three days of judgment…
Where there are TWO or three gathered in my name, there am I in their midst.
But then, idioms will be idioms.