Thou shalt no God but me adore:
‘Twere too expensive to have more.
No images nor idols make
For Robert Ingersoll to break.
Take not God’s name in vain; select
A time when it will have effect.
Work not on Sabbath days at all,
But go to see the teams play ball.
Honor thy parents. That creates
For life insurance lower rates.
Kill not, abet not those who kill;
Thou shalt not pay thy butcher’s bill.
Kiss not thy neighbor’s wife, unless
Thine own thy neighbor doth caress.
Don’t steal; thou’lt never thus compete
Successfully in business. Cheat.
Bear not false witness — that is low —
But “hear ’tis rumored so and so.”
Covet thou naught that thou hast not
By hook or crook, or somehow, got.

Ambrose Bierce (1842-1914?) American writer and journalist

“Decalogue,” The Cynic’s Word Book (1906)
    (Source)

Included in The Devil's Dictionary (1911). Originally published in the "Devil's Dictionary" column in the San Francisco Wasp (1881-12-02).

The poem is signed "G.J." in reference to Father Gassalasca Jape, S.J., a (fake) Jesuit priest Bierce often "cited" for poetry on religious topics. In his preface to The Devil's Dictionary (1911), he includes the note:

A conspicuous, and it is hoped not unpleasant, feature of the book is its abundant illustrative quotations from eminent poets, chief of whom is that learned and ingenious cleric, Father Gassalasca Jape, S.J., whose lines bear his initials. To Father Jape's kindly encouragement and assistance the author of the prose text is greatly indebted.

Robert Ingersoll was a famous agnostic and lecturer, frequently defended by Bierce in his newspaper columns.

In the original Wasp version, the Fourth Commandment read "Work not on Sabbath days at all, / Nor dare to read the Sunday Call." Bierce crowed in the next (1881-12-09) issue that at the same time as the poem was written, a newsdealer in Watsonville, Calif., was convicted of an infraction of the "Sunday Law" in selling that paper on the day of its publication. "We could hardly have hoped that our revised Decalogue would so soon be adopted as the law of the land."

Bierce returned to the theme in "The New Decalogue" (1887).

Have but one God: thy knees were sore
If bent in prayer to three or four.
Adore no images save those
The coinage of thy country shows.
Take not the Name in vain. Direct
Thy swearing unto some effect.
Thy hand from Sunday work be held --
Work not at all unless compelled.
Honor thy parents, and perchance
Their wills thy fortunes may advance.
Kill not -- death liberates thy foe
From persecution’s constant woe.
Kiss not thy neighbor’s wife. Of course
There’s no objection to divorce.
To steal were folly, for ’tis plain
In cheating there is greater gain.
Bear not false witness. Shake your head
And say that you have “heard it said.”
Who stays to covet ne’er will catch
An opportunity to snatch.