In Book Five, Section 129 of the Masnavi, Rumi employs the allegory of a Turkmen's watchdog to explain Satan's role in the divine order. Just as a watchdog is fierce and aggressive toward strangers but gentle and submissive to the children of the household, Satan acts as a guard at the door of the Divine. He possesses no independent power and cannot harm God's true beloveds ('the children of the house'), but he turns away strangers (the insincere or faithless). This metaphor highlights Rumi's theological view of absolute monotheism (Tawhid), where even the devil is ultimately an instrument of divine will, serving to distinguish the sincere seeker from the pretender.