One proof of how important the Pasig river is to the Filipino is the number of myths and legends we have that are connected with the river. Grace Odal identified a number of them in her article, The Mutya of the Pasig River: An Image of the Tagalog Water Goddess, which was published in the book, Pasig: River of Life.
Where Pasig got its name
In one origin of the Pasig River, it was said that it once separated two star-crossed lovers who loved each other so much that they decided to elope one night. Their boat capsized and the man fell into the river, calling his lover who went by the name Paz. He uttered “Paz sigueme (Paz, help me)” over and over until he drowned and his final words were: Paz sig…
How the Pasig came to be
Another origin stated that the river was made by a great serpent who made a pact with the Chinese and local merchants. The merchants grew tired of transporting their wares from Manila to Laguna and so the snake proposed to create a river where they can use ferries and travel faster. There was a condition to the proposal: at the end of their lives, the men were to give their souls to the snake. The merchants agreed and the snake created the Pasig river.
The Buwayang Bato was another famous legend. It narrated the story of a rich Chinese man who was a non-believer of the Catholic god and claimed that he was not afraid of crocodiles, an animal that was venerated by the locals. In one of the days when he was doing trade in some parts of the river, a big crocodile appeared and made its way to his boat. Afraid, the Chinese man prayed to San Nicholas for rescue and the crocodile turned into stone. He became a believer since then.
The Princess and the Sun god
A popular story on the Pasig was the story of Princess Dana, who conducts sun-rituals every morning. Every morning, the princess would go to the Rock of Bathala carrying flowers. After praying, she would bathe in the river. The King of the Sun made love to her one afternoon and got her pregnant. She was banished from the kingdom and her disappearance caused the flowers along the banks to wither away. She was asked to return and continued her sun worship.
Donya Jeronima of Guadalupe
A likewise popular and enchanting story was that of Donya Jeronima and her cave in Guadalupe. During her youth, Donya Jeronima had a boyfriend who was sent to Manila to study. Before he departed, the boy made a promise to marry her. When the lad didn’t return, Donya Jeronima searched for him and found out that he was already an Archbishop who gave her the cave near Guadalupe as her sanctuary. It was said that the Donya would wash the plates in the river by throwing them and it will come back to her clean and glistening.
Why there are no white lilies in Quiapo
Another story tells of the white lilies in Quiapo, who was believed to be a sign of peace, happiness and harmony. A leader named Loku ruled over the land and he started to believe in another foreign god. When they were attacked by foreigners, Loku could not ask help from the anitos and so they were defeated. The bodies of his warriors were said to have been placed above the lilies and stained the flowers. From then on, no lilies appeared in Quiapo. The locals eagerly waited for the return of the flowers in the belief that the flowers would bring back the peace, happiness and harmony it entailed. - As summarized by: Leilani Chavez
Source: The Mutya of the Pasig River: An Image of the Tagalog Water Goddess by Grace Odal, Pasig: River of Life edited by Reynaldo Gamboa Alejandro and Alfred Yuson