Sambandar wrote the hymn starting with the words "Bhogamartha Poonmulaiyal..." and included the phrase "Peru Petru Vilangukinra" (meaning: He who shines with great fame and grace ). The Result

The leaves were thrown into the Vaigai River . The rule was simple: the leaf that floated against the current (upstream) carried the ultimate truth.

The "2021 top" aspect of your query likely refers to its inclusion in contemporary digital collections of evergreen Tamil devotional hits, which remain staple listens during festival seasons. Peru Petru Vilangukinra - Sivappu Selaikari - JioSaavn