Through devotional service one can easily please Lord Krsna with a leaf of the tulasi plant and a little water. As the Lord says in the Bhagavad-gita (9.26), a leaf, a flower, a fruit or some water (patram puspam phalam toyam), when offered with devotion, very much pleases Him. He universally accepts the services of His devotees. Even the poorest of devotees in any part of the world can secure a small flower, fruit or leaf and a little water, and if these offerings, and especially tulasi leaves and Ganges water, are offered to Krsna with devotion, He is very satisfied. It is said that Krsna is so pleased by such devotional service that He offers Himself to His devotee in exchange for it. Srila Advaita Acarya knew this fact, and therefore He decided to call for the Personality of Godhead Krsna to descend by worshiping the Lord with tulasi leaves and the water of the Ganges.