How does Santiago complete this statement - "First you borrow,then..." ?

Let me complete the sentence first of all.'First you borrow,then you beg'.This is between Santiago and the boy.He interpretes that when a man borrows money or things though he does not earn or whenever the old man goes on fishing,he catches nothing.So from where he will bring money and return the debt.

So one becomes penniless and all resources of earning are chained,

then he comes into great trouble and for that in such tense he will

not consider begging as sin.He will be ready to beg for facing the debt.