Popol Vuh

Then they went, each one carrying his blowgun, and went down in the direction of Xibalba. They descended the steps quickly and passed between several streams and ravines. They passed among some birds and these birds were called Molay.

They also passed over a river of corruption, and over a river of blood, where they would be destroyed, so the people of Xibalba thought; but they did not touch it with their feet, instead they crossed it on their blowguns.