In plain words
Manomūlam idaṃ jagat: the world of the mind is the root and foundation of all the worlds. When we keep this world of the mind clean, holy and selfless, the whole world too will be holy. If we want to see this whole outer world green, we need not paint the whole world green. If we colour our own sight green, the whole world looks green. That is why creation is as the vision is. The śāstra is as our eye is. But we must try to keep pure the world of the mind's feelings within us. So, when we offer prayers with a holy mind, there is room for the principle of the Paramātma to bless. To pray as one in anguish is the main path. Yajñas, yāgas and such rites are but limbs of such prayer. This serves oneself and others. Here and hereafter. It is the joining of the two.
To be happy here, the learning that wins gold; to be happy hereafter, Brahmavidyā.
All worldly learning brings Ānanda only for this world. Brahmavidyā has the power to give Ānanda for the other world too. That is why kāmya karmas means the way that brings happiness and peace to oneself, to one's world and to one's own people too. So the pūjās we perform daily, the sixteen services of worship,
listening, singing, remembering Viṣṇu, serving His feet, worship, salutation, servitude, friendship and the offering of the self:
all these paths are merely kāmya karmas.
The third is niṣiddha karma. There are some things we must give up. The working of our mind depends on the food itself. That is why sāttvic food is most necessary. Sādhakas must give up completely all food bound up with rajoguṇa and tamoguṇa. They must give up drink, meat and all such intoxicating things. As the food, so the thoughts. As the thoughts, so the mind. As the mind, so the man. As the man, so the conduct. Our culture rests on conduct itself. Conduct joined with morality is most necessary for us. Speech joined with honesty is most necessary for us. Morality and honesty are the very eyes of man. Once we have lost this morality and honesty, humanness itself is wasted.