Leaving a slave bound and alone is not that unusual
Leaving a slave bound and alone, of course, is not that unusual. It may be used as a discipline, of course, but that is seldom the case. More often, it is used simply to impress upon her what she is, that she is a slave, subject to the will of her master. Often she does not know how long she is to be left bound, which muchly impresses upon her her helplessness and her dependence on the will of another, this demonstrating for her her vulnerability and utter subjugation.
Mariners of Gor, p. 112