The Chitra Pournami Meenakshi-kalyana narrative (originating sthala-purana)
Goddess Meenakshi (Madurai) sent her elder brother Kallazhagar a wedding invitation for her marriage to Sundareshwarar (Shiva). Kallazhagar walked the 21 km to Madurai but arrived after the wedding had concluded. Displeased, he refused to enter Madurai city and turned back at the Vaigai river — mounting his golden horse vahanam he entered the river and blessed the couple from the water; he then returned to Alagar Kovil.
