In case Bobby doesn't reply, it's Manx, which using a spelling system based on English - even though English spelling is not at all consistent phonetically. Irish would be 'slán leat' for goodbye (health/well-being to you). I don't know Manx Gaelic, but Scots Gaelic often uses the preposition "ri" in places where Irish uses "le"; thus "ris" (reesht) instead of "leat". Hopefully Bobby will tell us more.