In plain words
They have spoken of three kinds of sādhana for becoming steady in citta. The sādhana of the fish, the sādhana of the deer, the sādhana of the tortoise. The sādhana of the fish: it can live only while it is in the water; parted from the water for a moment, it cannot live even a moment at all. In just the same way, unless sādhana is done in solitude, this sādhana of the fish cannot be done among people. Unable to concentrate among people, developing concentration only when one is alone: that is the meaning of the sādhana of the fish. Then the sādhana of the deer: the deer moves about only on land, and will not move about in the water. So it becomes used to doing sādhana only among people. Then all the cares of worldly life, which are absent in solitude, crowd into the head. And the sādhana of the tortoise: whether it is in solitude, whether in the water or on the bank, it stays ready to live. It lives happily in both places. For one's citta to stay steady, whether in a crowd or in solitude: this is the right sādhana, and so they named it the sādhana of the tortoise. We go on developing just such an even citta. So, at this age, we must make the effort that sacred concentration needs. If you do not rein in the citta at this very age, reining it in during old age becomes impossible. So, at this time, when your physical, mental and spiritual powers are in their full vigour, you must make the efforts needed to rein in your senses. You must not fall prey at all to these movements of the mind, to these fickle states of citta. If you set out today fickle in citta, you will surely be those who have wasted life itself. When something happens against your feelings, or against your wishes, or against your resolves, you must not give way to the passions that surge up from within. Only when you act as one strong enough to rein in the passions that come will there be no doubt at all of your becoming worthy of God's grace. Today, even though we join with society, even though we do service to society, even though we live as members of society, we must keep the faith with which we offered our citta in a state where it does not waver in the least.