I'm having some difficulty understanding the construction of this sentence. Would there not have to be something between "leat" and "teacht" like "ag" or "go"? Can you just put a verbal noun in there (at least I think it's a verbal noun) in there like that?
When a verbal noun is used like an English infinitive and it doesn’t have its own object, then it can just be put in there like that. However, verbal nouns of transit (e.g. coming, going, etc.) used this way often appear with the preposition a anyway, e.g. Nach dúirt mé leat a theacht anoir?
Coming from the east anoir equates to going to the west, siar, in terms of geographical movement. But there might be a difference of intent: immigrating to New South Wales vs. emigrating from Ireland leave a different feeling for the same migration.