Classic Maya religion held that human blood was owed to the gods as nourishment and tribute, a debt incurred simply by being alive in a cosmos the gods had shaped and sustained, and that rulers in particular bore personal responsibility for repaying it through ritual bloodletting. The stingray spine, its natural barbs making a distinctive, deliberately painful wound, was the primary instrument for this rite, used to pierce soft tissue, the tongue, the earlobes, or, for men, the penis, so that the resulting blood could be collected on paper and burned as an offering, the rising smoke understood as carrying the offering to the gods and, in some depictions, opening a visionary channel through which an ancestor or deity could be summoned to appear.
The clearest surviving record of the practice is a set of carved stone lintels from the site of Yaxchilan, commissioned under the eighth century ruler Bird Jaguar and his father Shield Jaguar, showing royal women drawing a rope studded with obsidian or bone barbs through a wound already opened in the tongue, an act depicted alongside the ruler himself performing a comparable bloodletting from his penis, together framing the rite as a shared obligation of the ruling couple rather than a duty falling on the king alone.