Unlike later grimoires such as the Pseudomonarchia Daemonum (16th century) or the Lemegeton (17th century), the Key of Solomon does not mention the signature of the 72 spirits constrained by King Solomon in a bronze vessel. As in most medieval grimoires, all magical operations are ostensibly performed through the power of God, to whom all the invocations are addressed. Before any of these operations (termed "experiments") are performed, the operator must confess his sins and purge himself of evil, invoking the protection of God.