Tá na baggies ar an talamh!
I started to write the same but you beat me to it. Maith an fear.
Is this an idiom like the German "das Geld liegt auf der Strasse" - literally "the money lies on the street", meaning "there is an opportunity to make money everywhere"?
Isn't ar an followed by lenition? Or eclipsis?
Yes, it should be eclipsed in other cases, but not if the word begins with a "d" or a "t".
Unless it's Munster, which does eclipse all.