Please explain this quote from "The Devil and Tom Walker":
"The Devil presided at the hiding of the money, and took it under his guardianship; but this it is well known he always does with buried treasure particularly when it has been ill-gotten."
Perhaps the "buried treasure" to which the narrator alludes includes a metaphor for the hidden darkness of the sin of greed as well as some buried wealth. Whenever Captain Kidd entered the inlet mentioned in the exposition and buried his treasure, the Devil appeared "to have his due" as the old expression goes.
Therefore, when Tom Walker discovers the treasure for which Kidd never returned, the "black man" reappears as there is a new soul for him to take. Tom argues that he is trespassing on the property of Deacon Peabody, but Old Scratch points to where Peabody is buried in return.
"This woodland belonged to me long before one of your white-faced race put foot upon the soil."
After "a long and earnest conversation" together, the treasure is offered to Tom on certain conditions and the devil places his "signature" upon Tom's forehead with the black imprint of a finger. This mark makes it necessary for Tom to recount what happened to him in the forest to his wife. Having heard this news, "she determined to drive the bargain on her own account" and went into the woods; however, she did not return because she did not agree to be under the "guardianship" of Old Scratch. But Tom, who has agreed to be a usurer, makes a fortune. Unfortunately for him, as is always the case, the Devil continues to "preside" over his soul and comes one day to collect his due. There are three loud knocks at Tom's door and "the black fellow" tells Tom, "you're come for" as Tom tries to run. But he never returns despite having been seen on his horse galloping "like mad across the fields." Tom Walker, too, cannot escape "the guardianship" of his soul by the Devil.