As Muslims we must bear in mind the fact that Zakah is one of the pillars of Islam. In fact, it is the third pillar of Islam after testifying that there is no god but Allah and Muhammad is His final Messenger and offering Prayers five times a day. The Prophet (peace and blessings be upon him), said, “Islam is built upon five pillars: testifying that there is no true god except Allah and that Muhammad is the Messenger of Allah, performing Prayer, paying Zakah, making the pilgrimage to the Sacred House (Hajj), and fasting the month of Ramadan.” (Reported by Al-Bukhari)
Shari`ah commands that zakah should be paid from the deceased’s estate before its distribution among the heirs. Since Zakah is the right of the poor on the wealth of the rich, the death of a wealthy person does not absolve him of his obligation to pay the amount of Zakah required of him.
According to Imam Ash-Shafi`i, Ahmad, and Sabiq, if one dies before paying Zakah, then the unpaid Zakah should be taken out from his estate and paid to the poor before the estate is distributed among his heirs.
Al-Bukhari and Muslim reported that a man came to the Messenger of Allah (peace and blessings be upon him) and said, “My mother died while she has to make up for one month of fasting. Shall I make it up for her?” The Prophet replied, “If there was a debt upon your mother, would you pay it off for her?” The man answered: “Yes.” The Prophet then said, “A debt to Allah is more deserving to be repaid.