In plain words
Cultivating cleanliness in the food one cooks. We must attend to some extent to purity of the vessel, purity of the ingredients and purity of the cooking. Man must keep clean every single thing he uses in his daily life. Not things alone: when we are at our studies, we must keep our books clean. This is physical cleanliness. However many of these purities there may be, if inner purity itself is lacking, it is of no use. From the scholar right down to the unlettered man, everyone strives only for outward purity, and does not strive in the least for the purity within. However clean you scour the vessel and set it out, if this vessel has no tin lining, all this food cooked in it becomes useless. So cleansing the vessel called the heart is the chief sādhana. To cleanse it we must enter into selfless service. Through attachment and hatred, Manas and Buddhi become soiled. We must purify such impure Manas and Buddhi through selfless services. Only when Manas and Buddhi are pure can a man take part in desireless service. When Manas and Buddhi are impure, the karmas we do take shape only as impure ones. So the purity of body and of mind is man's chief duty.
The third is niṣṭhā. That is, every man must take up a niṣṭhā in his life. For as long as life lasts, the feeling must arise in every single man that we should enter into sacred works, take part in service to the people, and so nourish meritorious deeds. We must build up the faith that through service to the people we can attain the oneness of man. Through service to society oneness is gained. It is through oneness alone that divinity can be attained. We must regard the very attaining of this divinity as sacred. So, as long as every man lives, 'This body is for the good of others': we must hold that this body has come as something meant for helping others. When man is absorbed only in these two, selfishness and self-interest, how then can he recognise the real principle called the good of others? We must sacrifice selfishness. If we wish to make this sacrifice, we must take part in service to society.