In plain words
In later times Rāmānuja amended the doctrine of Advaita that Śaṅkara had taught and went on calling it viśiṣṭa Advaita. Śaṅkara said Advaita is sugarcane juice. How long can this be kept? It is not lasting. It is not the juice of amṛta. He said it must be turned into something full of amṛta. Refine the sugarcane juice, turn it into sugar, and add it to anything. Put it in rice flour, put it in wheat flour. It will be sweet. Whatever you put it in, its quality is sweetness! This sugar is lasting. You can use it for anything. This is what they called pure, viśiṣṭa Advaita. I shall explain each of these in full and teach them to you. The third is Dvaita. The one who founded it was Madhvācārya. Śaṅkarācārya, Rāmānujācārya, Madhvācārya. These three founded three religions: Advaita, Viśiṣṭādvaita and Dvaita. Yet all three accepted one and the same thing. That same juice, they said. But Madhvācārya: ‘I should not become the sugar. I must be the one who eats the sugar. I must enjoy the sugar. If I am the sugar, how can I get any joy? So make me one who relishes the sugar,’ he said. When can you change into one who eats the sugar? Only when a man offers himself up does he become one who eats the sugar. Until then, not at all. Do as many kinds of sādhana as you like. Do as much tapas as you like. Do as many yogas as you like. Do any number of japas and dhyānas. Read any number of books. But the right to eat that sugar does not come. All these are ways of holding back the mind for a time. But since all sādhanas take place through the mind, you must offer that mind to God. This is just what Madhvācārya said:
Whatever heart You gave me, O Lord, that very heart I offer back to You, O glorious One; what else could I bring for the worship of Your feet? I join my palms in añjali: receive it, Lord.