feet (or foot?) of debt

[shootingstar]

. . .
It was in these circumstances that, with all brevity of speech and a certain boyish sullenness of manner, looking the while upon the floor, I informed my relatives of my financial situation: the amount I owed Pinkerton; the hopelessness of my maintenance from sculpture; the career offered me in the States; and how, before becoming more beholden to a stranger, I had judged it right to lay the case before my family.
"I am only sorry you did not come to me at first," said Uncle Adam. . . . "Yes," he pursued, "and here is something providential in the circumstance that you come at the right time. In my old firm there is a vacancy; they call themselves Italian Warehousemen now," he continued, regarding me with a twinkle of humour; "so you may think yourself in luck: we were only grocers in my day. I shall place you there tomorrow."
"Stop a moment, Uncle Adam," I broke in. "This is not at all what I am asking. I ask you to pay Pinkerton, who is a poor man. I ask you to clear my feet of debt, not to arrange my life or any part of it."
. . .
(Robert Louis Stevenson and Lloyd Osbourne, The Wrecker, Chapter VI: In Which I Go West)

What does feet of debt or foot of debt mean there? Is it an idiom?
Thank you.

 

[Skrej]

You're parsing it incorrectly. Read it as 'clear my feet of debt', not just 'feet of debt'.

It is a metaphorical reference to either his debt miring him like mud in a bog, or perhaps his debt being like a pair of leg irons. At the time the story is set, imprisonment for debt might have either still been in practice, or if no longer actually in practice, still in the common collective memory - "pop culture" of the time, if you will.