Anyone know the origin of this dharani? (Dharani is a long mantra or incantation.) I recognize some of the koreanized Sanskrit, but can't make it most of it.

It's chanted daily in temples all over Korea. Some of the most famous Korean Zen masters chanted this dharani tens of thousands of times.

Any information about it would be greatly appreciated!

I asked around in Korea, but nobody seems to know!

Hapjang,
Cheondo

could it be the great compassionate dharani? it's also called mahakaruna in sanskrit.

if you means Shin Myo Jang Gu Dae Da Ra Ni ? Great Compassion Incantation / Mahakaruna Dharani / 神妙章句大陀羅尼/ 신묘장구대다라니

It is part of the esoteric school, The full name is ' Thousand-Handed and Thousand-Eyed Avalokitesvara Bodhisattva's Vast, Perfect, Unimpeded, Great-Compassionate Heart- Dharani Sutra' / 千手千眼觀世音菩薩廣大圓滿無礙大悲心陀羅尼經
with common name as 'Great Compassion Dharani / Mantra ' or ' Da Bei Zhou'
Here
It was rendered around 650ce by the Indian Bhagavad- dharma into Chinese.
Some explanation
and you could easily find many in the YouTube for your comparison
Vietnamese version known as 'Chu Dai Bi' - interesting



ASN

Thanks a bunch, Ansanna!
Wow, great explanations, sanskrit, AND a word-by-word translation
Amazing! More than I hoped for.
Now I can know what I'm saying! haha.

Hapjang --
Cheondo