Why is Lord Vishnu worshipped as the Shaligram stone during Tulsi Vivah?

The Shaligram stone is the living reminder of Vrinda’s curse and Lord Vishnu’s willing acceptance of stone-form as penance for deceiving her. In Tulsi Vivah, Vishnu returns to his beloved Vrinda (now Tulsi) in this stone form — completing the cycle of separation, curse, and reunion. By formally marrying the Shaligram (Vishnu) to the Tulsi plant (Vrinda), devotees honour the cosmic love story and perform the “righting” of the deception. The Skanda Purana states that performing this annual marriage confers wealth, food grains, and lasting renown upon the devotee’s family. It is also believed to remove the dosha of any father who did not perform his daughter’s kanyadaan during her lifetime.