Srimad Bhagavatam says that it is far better to use tulsi leaves than sandal paste for worship of Lord Narayana, said P.T. Seshadri in a discourse. There is a story in the Narada Purana that brings out the greatness of tulsi. In a village, there lived a Brahmin called Madhava. He had never done any good deeds in his life or observed any rituals. He had some lands, which he cultivated. Everyday, he brought grass for his cows when he returned home.
One evening, he accidentally cut some tulsi leaves along with the grass. He was destined to die that evening and a snake came slithering towards him to bite him and end his life at the predetermined time. But it could not bite him because he had tulsi leaves in his hand. The man picked up the bundle of grass, together with the tulsi leaves, and placed the bundle on his head and went home. The snake hid itself in the bundle, hoping to bite him when he laid it down. Near Madhava’s house lived Madhusudana, a very pious man. Through his powers, he realised that there was a snake in Madhava’s grass bundle. He could even see the Yamadhutas shadowing Madhava to take away his life the moment he was bitten by the snake. Madhusudana asked the Yamadhutas how to save Madhava’s life. The Yamadhutas replied, “We know that you do tulsi puja every day. If you transfer to Madhava the benefits of your tulsi puja for today, then he can be saved.” Madhusudana then transferred that day’s merits to Madhava and the latter’s life was spared. Madhusudana then told Madhava what had happened and urged him to do tulsi puja every day. From then on, Madhava too did tulsi puja every day. Nrisimha Purana says that while bilva leaves, darbha grass and tulsi are ideal for worshipping Lord Narayana, tulsi is the best.