By Swami Harshananda
On this day, Tulasī or Vṛndā was married to Hari or Viṣṇu. So, it is also called as Tulasīvivāha day. Ceremonial marriage of the Tulasī plant with Lord Hari is performed on this day. In some houses, images of Hari and Tulasī are kept for three days from the navamī to ekādaśī and worshiped. They are married on the dvādaśī day.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore