Where does the phrase “I Cross My Heart and Hope to Die” originate from?

According to someone on yahoo, it comes from a long poem or prayer back in the 1900, https://answers.yahoo.com/question/index?qid=20100901201717AAUQnEi

Wait, someone pointed out that it can’t be early 1900 because they used the term, give it a shot. Which is a more current term. Another person says it’s just a childhood rhyme. Interesting.

It sounds very much to me like something from one of those rope skipping chants.

Cross my heart and hope to die does have some religious tones. Like the crossing of ones heart in the symbol of Christ. So I imagine, when you make a promise to keep a secret, you are saying that you swear upon the cross and may you suffer the pain of a needle piercing your eye if you reveal what you have seen.

Must be a similar story to this, which is rather disturbing.
https://en.m.wikipedia.org/wiki/Now_I_Lay_Me_Down_to_Sleep

Good question. The vague answer below seems to be echoed throughout the net on YahooAnswers, Quora, Dictionary.com, HubPages and in various blogs:

“According to the American Heritage Dictionary of Idioms, (AHDoI) this phrase most likely originated as a religious oath based on the sign of the cross; it is generally accompanied by hand gestures such as crossing one’s hands over one’s breast and then pointing the right hand skyward (a variant is Cross my heart and point to God). Today most often uttered by children, it was first published as a poem in 1908.”

I have a problem with this answer because (1) It is repeated almost verbatum everywhere I find it and therefore it’s veracity and provenance is automatically under question. All that’s missing is the poor grammar and spelling. But that’s just me. (2) The American Heritage Dictionary of Idioms would have given the name and author (even if anonymous) of the poem and more on the publishing history. “first published as a poem in 1908” just doesn’t reflect the thoroughness of a respected reference such as the AHDoI.

This idiom appears in Canada, as well. There is also evidence of a French version:

“A form of it is found in France, too : “Croix de bois, croix de fer, si je mens, je vais en enfer” (Cross of wood, cross of iron, if I lie may I go to Hell). While the wood and iron thing is probably just a bit of nonsense to make it rhyme and have the right meter/rythm, it was traditional to do the sign of the cross twice when saying this.” —The Straight Dope

I would go to the AHDoI to continue research at this point, but I don’t have a copy, the AHDoI isn’t online and there are no libraries here. So my research ends here. Maybe @Jeruba has a copy lying around.
There is no

Here’s a version of the poem (copypasta):

I cross my heart

And hope to die

Stick a needle

In my eye

Wait a minute

I spoke a lie

I never really

Wanted to die

But is I may

And if I might

My heart is open

For tonight

Though my lips are sealed

And a promise is true

I won’t break

My word to you

But if by chance

I should somehow slip

Accidental words

Tumbling from my lips

If this solemn vow

I should break

Then no more breaths

Shall I take.

Thus you know

This promise is not a lie

For I am not

Prepared to die.

Really good question, Keith.

@Espiritus_Corvus Thanks and what a great answer.