Anyone ever hear this phrase: "If you mean to do a thing..."

Another thread asked about things your grandparents used to say. I only knew 1 of my grandparents - my mom’s dad, who died when I was 8.

He used to say something that I remember as:

“If you mean to do a thing,
and wish to do it really.
Never let it be by halves,
But do it fully, freely.”

My sisters remember him saying the same thing - and probably my mom (also dead) saying her dad said it.

Anyone ever hear this and have any idea where it is from?

If you to google this,
the first line gets no hits.
But if you do the final line,
the results are the tits.

To paraphrase the guy next door from Office Space,* “Hell, no, Man! I believe I’d punch somebody in the mouth if they said that to me.”*

I’ve heard that. Don’t know where. Maybe I read it?

The third line gives even more hits than the second, including an expanded (but unattributed) version here. This one attributes it to Phoebe Cary and this one attributes it to her sister [DEL]Ursula[/DEL] Alice Cary. The poem is not in the book of their collected poetry, so probably both attributions are wrong. (But nobody tell this kid that.)

Aaaand, there is a different book of their poetry that does include it, attributed to Phoebe (though only the 8-line version, not the much longer one.)

(Last one) it seems to be mainly published in religious training materials, including this 7th Day Advantist periodical from 1871, which includes the long version, unattributed. I’m thinking that the additional lines were added by someone else.

So is this just a rhyming version of “Any job worth doing, is worth doing well.”?

More a version of “do what you are told, now, damnit!”