Leonidas hand picked the 300 because they were all FATHERS.
The men all left sons behind who would carry on the blood line of the brave men.
For those who don't know this is where we get the phrase MOLON LABE. (come get them) This was when the persians demanded the spartans surrender and leave their weapons behind. The spartan replied by saying come get them.
There is much MISinformation about the ancients (having studied the real deal in Greece). So be wary of folks who are too quick to view the ancient world with revisionist history lenses.
Would today's equivalent be "bring it on!"