Sharpen the head, ripen the heart
A fruit-bearing creeper when carefully tended gives a ripe fruit. Similarly, our devotion to Krishna when carefully tended gives an eternal life of love with Krishna.
When tending to a creeper, we remove the weeds and provide adequate nourishment. Similarly, when tending to the creeper of devotion, we need to remove the weeds of anti-devotional desires and provide adequate devotionally nourishing stimuli.
This essentially means sharpening the head so as to ripen the heart. The Bhagavad-gita (15.03) urges us to use the weapon of detachment to cut away our entanglement in material existence. So that, as the next verse (15.04) indicates, we can lovingly surrender to Krishna.
To know what to detach ourselves from, we need to sharpen our head. That is, we need to increase our intellectual sharpness so that we can distinguish the eternal from the temporary, the spiritual from the material, the devotional from the pseudo-devotional. Regular study of scripture keeps our head sharp and enables us to resist temptations and distractions whenever they appear.
To help the creeper of devotion grow, we need to nourish it with devotional nutrients centered on the remembrance of Krishna. The more we remember Krishna, the more our attraction for him increases. The easiest way to remember him is by chanting his holy names. The daily discipline of chanting is the like daily watering the garden of the heart.
By such sustained spiritual cultivation, the fruit of love for Krishna appears in our heart and starts to ripen. The riper it becomes, the more we relish it even in this life, what to speak of the next. And the more we relish it, the more we inspire others to similarly relish the sublime joy of devotion, thereby demonstrating that this delicious inner fruit is inexhaustible.
“The real form of this tree cannot be perceived in this world. No one can understand where it ends, where it begins, or where its foundation is. But with determination one must cut down this strongly rooted tree with the weapon of detachment. Thereafter, one must seek that place from which, having gone, one never returns, and there surrender to that Supreme Personality of Godhead from whom everything began and from whom everything has extended since time immemorial.”