Don't play with matches, or you might get burned.
This truth applies beyond the realm of matches,
beyond the realm of tools in general.
But how many of us do it anyway?
A match is a thing that, when put to its proper use,
can be of extreme, even life-saving, value...
But when handled recklessly presents mortal danger.
Onan played with matches.
And Onan surely got burned!
But what was Onan's match?
Talmudically speaking, it was his seed,
Whose proper purpose was the bearing of children,
But instead he spilled it on the ground.
But there is so much more to that story!
Judah had three sons: Er, Onan, and Shelah.
Judah got a wife for his firstborn Er, and her name was Tamar.
Er was evil in the sight of G-d, so G-d took his life.
Then Judah instructed Onan,
"Do your duty, and marry your brother's widow, that his progeny may live on through you."
But Onan knew that the progeny would not be his,
So whenever he came to Tamar, he spilled his seed on the ground
in order not to give seed to his brother.
What Onan did was evil in the sight of G-d, so He took his life also.
The same Hebrew word "rah," meaning "evil," is used to describe
the person of Er and the action of Onan.
What did they have in common?
They both denied Tamar children,
which at the time also meant they denied her a livelihood,
as she would have no right of inheritence on her own.
It is left unsaid how or why Er did this;
nothing about spilling his seed.
Perhaps he simply ignored his wife.
After all, his father had gotten her for him.
Why didn't the text simply say Er had a wife?
Why tell us that Judah got her for him?
Because Er had no regard for anyone but himself.
He cared neither for his father, nor for any future children of his own, nor even for his wife.
Er was, as the text tells us, just a bad person.
Onan, on the other hand, was not a bad person; only his actions toward Tamar are described as evil.
In the eyes of G-d, is this a distinction without a difference?
Why did He take Onan's life as well?
But there was another difference:
Er's action was without precedent,
but Onan saw Er err,
and then saw him die.
Thus while Er acted in semi-ignorance,
Onan knew precisely what consequences his actions might bring.
Just as a child knows that playing with matches might mean getting burned.