I came across this in Breandán Breathnach's book Ceol Rince na hÉireann 2. I was looking for tunes from around our area and found this one Brendán had collected from Molly Meyers Murphy. It's a lovely and simple and when you play it slow you can hear that it came from some old song.. There's loads of great tunes in that book and especially the ones from Mrs Murphy - they all have a lovely unadorned wild thing about them - Pure Sliabh Luachra. https://en.wikipedia.org/wiki/Breand%C3%A1n_Breathnach
I first taught this as part of a workshop I did at Scullys Fest back in 2018 called "Rare and Quare Tunes".