ID

Here is David, says the guide.
Nonsense! David was a boy,
11, maybe 12; this is a grown man.
One who is quite wondrously fit,
And also 14 feet tall. In other words,
He is a giant -- "Il Colosso,"
The Florentines called him.
It can only be that this fellow
Is Goliath, escaped from the version
In which, to show his disdain
For his opponent, he arrives
Fresh from the bath, not bothering
Even to put on a towel.
Instead of a sword, he carries a sling.
He does not intend to kill David --
Where would be the glory in that?
No; he just wants to teach the boy
The unwisdom of challenging giants.