Ushasti said: 'Give me to eat of them.' He gave him the beans, and said: 'There is something to drink also.' Then said Ushasti: 'If I drank of it, I should have drunk what was left by another, and is therefore unclean.'

In plain words: The starving Ushasti asks the chief for some of his leftover beans, and the chief gives them. When the chief also offers him water, Ushasti refuses, because drinking someone's leftover water would make him ritually unclean.