"They had a proverb: 'Not as Áed Bennán has left his sons'."
There is no linguistic analysis of this particular proverb that I'm aware
of, if that's what you wanted to see. She (Nike Stam) does offer a
historical explanation, namely that Áed's sons (there are as many as twelve
of them in this text) were deprived of their inheritance as a result of
certain power struggles.
FYI, the thesis is available online from a digital repository of Utrecht