Just In Case

Dumbledore first says "Just in case" to refer to Harry's possession of the Invisibility Cloak when he returns it to him, after Harry accidentally leaves it at the top of the Astronomy Tower. He also suggests that Harry bring it with them to see Professor Slughorn, "just in case," and tells Harry to keep it with him at all times during his sixth year at Hogwarts, "just in case." This seems to allude vaguely to Dumbledore's tacit wish for Harry to pursue adventures that could get him in trouble. Perhaps this has to do with his knowledge of Harry's destiny--he must see it as his duty to cultivate a spirit of adventure in Harry, who is prophesied to challenge Voldemort.

But the phrase potentially also speaks to Dumbledore's temptation by the Deathly Hallows. "Just in case" suggests to me that he feels the need to justify his actions, and that he says those exact words three times suggests almost a mantra. It seems almost as if Dumbledore is a recovering addict, once intoxicated by the proximity of the Hallows. When he meets up with Harry before they go to see Slughorn, he is in possession of the ring with the Resurrection Stone as well as his wand, which is the Elder Wand. If Harry brings the Cloak, the two of them actually have the three Hallows, between them--and the ring is a recent acquisition. Dumbledore's request that Harry keep the Cloak with him during his sixth year, then, almost implies to me that he did not want to be tempted by the knowledge that it might be tucked away, where he could find it, as much as for Harry's own purposes.

Perhaps coincidentally, Hermione also suggests that they Disapparate under the Invisibility Cloak "just in case," when they move to the Forest of Dean in DH19.

--AK