Ata' bin Abi Rabah عطاء بن أبي رباح · The Book on Fasting

"A woman came to the Prophet and said: 'My sister died while she had two consecutive months of fasting due.' So he said: 'Do you not see that if there was a debt due from your sister then you would have to pay it?' She said: 'Yes.' He said: 'Then the right of Allah is more appropriate.'"

The Messenger of Allah said: "Whoever provides the food for a fasting person to break his fast with, then for him is the same reward as his (the fasting person's), without anything being diminished from the reward of the fasting person."