Do link que você forneceu:
O ponto não é que os mendigos estão na Espanha, mas meramente: "devemos aos pobres e aos infelizes qualquer coisa?". A Espanha é apenas um outro local arbitrário usado na citação original da qual o autor tirou o título.The novel's title comes from its primary moral question, as presented by character Tony Indivino: what do productive and responsible members of society owe the "beggars in Spain," the unproductive masses who have nothing to offer except need? This is only underscored by the rift between Sleepers and Sleepless; Sleepless are superior in mind and body, and easily capable of outperforming their normal cousins. All men are not created equal. Where, then, is the line between equality and excellence? How far should any superior minority hold themselves back for fear of engendering feelings of inadequacy in their inferiors?—especially if this minority is not hated and feared, but rather the elite? This question is explored, but not elaborated on by the novel.
Não é uma expressão em inglês, se bem me lembro.