What is the ruling on offering money and food to the family of the deceased and recording it as a debt, then repaying it when one of those who offered this assistance passes away?

If the gift or money is for consoling the family of the deceased and showing kindness to them, then there is no harm in it, whether they are poor or preoccupied with their calamity. The Prophet (peace be upon him) commanded that food be prepared for the family of Ja'far. However, if the gift is conditioned upon its return in a similar calamity, or if it is a loan conditioned upon repayment, then it is better to avoid it.