'Duty' in the Bible

"Let it be so on this occasion," Jesus replied; "for so we ought to fulfil every religious duty." Then he consented;

“Again, you have heard that it was said to the men of old, ‘You shall not make false vows, but you shall fulfill your vows to the Lord [as a religious duty].’

and forgive us our shortcomings, as we also have forgiven those who have failed in their duty towards us;

And [you scribes and Pharisees say], ‘Whoever swears [an oath] by the altar, that is nothing (non-binding), but whoever swears [an oath] by the offering on it, he is obligated [as a debtor to fulfill his vow and keep his promise].’

Your duty then was to deposit my money in some bank, and so when I came I should have got back my property with interest.