When is an allusion not an allusion? This question forms a powerful undercurrent in a good deal of New Testament study. The historical question (was Paul, or whoever, alluding to a particular text, and if so why) is often intertwined with literary questions about authorial intention and the like; about these things. As the writer to the Hebrews says, we cannot now speak in detail. It is highly probable that writers in second-Temple Judaism alluded to a good many biblical texts, deliberately conjuring up a world of discourse with a word or phrase. It is also highly probable that readers in the twentieth century, alert for such allusions, will hear at least some where none were intended. It is absolutely certain that modern readers who are alert to this danger, and hence unwilling to allow any allusions beyond more or less direct quotations, will radically misread important texts. There are times when the historian needs reminding that history is an art, not a science.
(N T Wright, Jesus and the Victory of God, 447)