Whoever will bring a story to you will take two stories from you.
Note: This is more an Irish protocol than a proverb. If someone tells you a story, then you are expected to tell two in return. It is similar to the Irish greeting protocol; if someone greets you with a blessing, “Dia duit” (God to you) then you are expected to return a greater blessing, “Dia’s Muire duit” (God and the Blessed Virgin Mary to you). Another interpretation suggests that the two stories taken from you are the one you told and the one the story-teller told. In any case, you are expected to give at least as good as you got.
John Millington Synge discovered this cardinal principle of Irish hospitality when he visited the Aran Islands. His muse had deserted him in Paris when Yeats suggested he seek her in these remote islands in the Gaeltacht. Synge spent the next four summers learning Irish on Inishmaan (Inis Meáin). His Island hosts wanted to hear his stories about the continent. In return, they regaled him with the folk tales of the Islands. At least four of them ended up as plots in his plays.
“The Playboy of the Western World”, for example, was based on a story Synge heard of a young Connaught man who had actually murdered his Father with a spade in a wild rage. He fled to Inishmaan and asked the Islanders to save him from the despised English law. They hid him in a hole for several weeks until they could arrange his clandestine passage to America. “If a man has killed his father, and is already sick and broken with remorse, they can see no reason why he should be dragged away and killed by the law.”1
1John M. Synge, The Aran Islands, republished by Dover, 1998, p. 44.