Where in huck finn does it talk about the cross on the shoe print?

Chapter 4, brief tell,

Huck is progressing with his new life with the Widow and even gets a little school done. One winter morning, he sees footprints, with an imprint of a cross formed by what seems two nails on the left heel only. A symbol he reconizes. After selling all his share of money after his encounter with Engine Joe, to Judge Thatcher for a dollar, he runs to Jim to tell him about the cross, in which he recognizes as his father close by.