What is the ruling on delaying the payment of a deceased person's debts from their estate for the purpose of investing it, and what is the advice of Sharia for the children in this situation? Is it permissible to make a will with bid'ah (innovative) matters, such as giving charity on specific days or months?

The heirs must hasten to pay off the debts of the deceased before distributing the inheritance, as stated in the Holy Quran: (after any bequest which he may have made or any debt), and the hadith: "The soul of a believer is tied to his debt until it is paid off." If the debts consume the entire inheritance, then all of it belongs to the creditors. The heirs sin by delaying the payment of the debt. The deceased does not sin if they did not neglect to pay their debt and bequeathed its payment; the sin falls upon the heirs if they do not fulfill the bequest. A bequest that involves something unlawful or an innovation is not permissible and must not be carried out; for there is no obedience to a creature in disobedience to the Creator.