i found a version in 20 lines, of "the Mistery", it is quite different from the one i was told about, (electronic irish text on line), anyway the 17th line goes like that:
Am nómá tonnag sírthintaghaív
so, is it the 'v' a letter used in old irish, or it is a simple mistake in the book where this version was quoted from? thanks for a possible help d.