All perfect praise be to The Lord of The Worlds, and may His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Prophetic Sunnah urges Muslims to console the family of the deceased and not to burden them beyond their capacity because they are busy with the matter of their deceased.
In such sad occasion, it is from Sunnah that the distant relatives of the deceased or his neighbors make food for his family, as indicated in the following Hadith: When Ja’far was killed, the Messenger of Allah (PBUH) went to his family and said: ‘The family of Ja’far are busy with the matter of their deceased, so prepare food for them.’{Sunan Ibn Majah}.
In principle, the family of the deceased isn`t expected to make food for anyone; however, if nobody made food and some relatives came from distant places to offer their condolences, then it is permissible to make food for them.
This is provided that they don`t compete in making the food and it doesn`t become a matter of boasting.
Moreover, it isn`t permissible to pay for that feast from the wealth of the deceased`s heirs, unless they approved of that, nor that of his minors. In addition, the deceased doesn`t incur sin because of what his son did.
In conclusion, we advise people to console the family of the deceased and not to burden them. In addition, the deceased isn`t held liable if his son had borrowed money to make the aforementioned feast on his behalf. However, if he did that out of charity, then he should expect his reward from Almighty Allah. And Allah knows best.