Deuteronomy 15:2,3

‘ And this is the manner of the release. Every creditor shall release that which he has lent to his neighbour; he shall not exact it of his neighbour and his brother, because Yahweh's release has been proclaimed. Of a foreigner you may exact it, but whatever of yours is with your brother your hand shall release.'

The release is to be granted to neighbours and brothers, not to foreigners. Again we must recognise that such borrowing between Israelites would only take place under circumstances of real need. It was not in that sense a ‘borrowing' society. Thus the probability is that if the person had been unable to pay it back by the seventh year it would indicate deep poverty. That is why Yahweh in His goodness proclaims freedom from the debt. It was not a rogue's charter, and the creditor, who was presumably himself doing well, was to willingly forego the debt, recognising the great need of the debtor, because he was grateful for what Yahweh had given to him.