In
The Book of the Sacred Magic of Abra-Melin the Mage Abraham warns his younger son about the power of symbols. Abraham illustrated the manuscript he wrote for his youngest son, a manuscript Abraham thought would make up for the fact that the older son would inherit all material possessions.
In Abraham's words:
All these symbols are to be either buried in the ground or placed under doors, steps, or buried under paths and other places by which people do pass, or whereon they lean. . . . But should you do this to please some friend, Abraham warns his son, you would not escape easily with impunity from the disapproval of your Guardian Angel.
