This is one I've been wanting to ask about for a while. There's a pub in Berlin (near where one of my sons lives) with a website and on their drinks page they give a quotation which they say is by Behan. You can find it on other websites in German, so it seems to be quite widespread over there. Try as I might, I just can't find the original anywhere, so if anyone knows where it comes from, I'd be grateful if they could tell me and if it's even from the man himself.
The pub is The Lir, and this is the page in question -
www.thelir.de/de/drinks.html"Wasser ist nicht zum Trinken da, sonst hâtte Gott nicht so viel davon gesalzen"
which I'm guessing would be something like - "Water isn't for drinking or why would God have put so much salt in it". To me it looks as if he could be referring to seawater, but I don't know.
Anyway I'll try and put it into Irish (and ten years from now, I wouldn't be surprising to find somebody out there quoting it as a traditional Irish proverb).
Ní an t-uisce le haighaidh a ól nó cén fáth chuirfeadh Dia salann níos mó air.
(is that getting anywhere near the original?)