An allusion is a literary device employed to associate a character, place or object in a story with a character, place or object, often from another literary source. One of the first, and most obvious or blatant in Charles Dickens' A Christmas Carol, occurs very early in the story, specifically within the context of the narrator's discussion of the passing of Jacob Marley and the role of Ebenezer Scrooge in attending to his late business partner's affairs. In the passage in question, Dickens, repeatedly emphasizing the fact of Marley's death, and, as it turns out, presaging the events to follow -- in this case, the imminent appearance of Marley's ghost -- makes a literary reference to a well-known play by William Shakespeare:
"There is no doubt that Marley was dead. This must be distinctly understood, or nothing wonderful can come of the story I am going to relate. If we were not perfectly convinced that Hamlet’s Father died before the play began, there would be nothing more remarkable in his taking a stroll at night . . ."
In this passage, Dickens narrator makes an allusion to Shakespeare's Hamlet, the title character of which embarks upon his fateful journey to avenge his father's murder after encountering the ghost of his father and learning the truth of the deceased's demise. Now, this is, as noted, the most obvious example of allusion in A Christmas Carol, but is far from the only one. Indeed, it could be surmised that Dickens intended the name of his main character to reference the Biblical book of 1 Samuel, which seems to associate the word "Ebenzer" with the might and blessing of God, occurring as it does within the context of the Prophet Samuel's role in the Israelites' defeat of the Philistines. The Israelites were in and out of trouble with God for quite a lengthy period of time in the Bible, and Dickens' use of "Ebenezer" for his protagonist's name could have been meant to presage the character's eventual spiritual redemption.