What is the difference between what is permissible and what is prescribed?

Question : If someone asks, “What is the difference between your saying that it is permissible and your saying that it is prescribed?” This is a very important point.

Answer : We say that what is permissible is that in which permission is granted to do it, but it is not required to do it. What is permissible is that in which permission is granted to do it without it being required. What is prescribed is that in which it is required to do it. We give an example of this: the issue of i'tikaf (spiritual retreat in the mosque). The Prophet (peace and blessings be upon him) permitted 'Umar to perform i'tikaf in other than Ramadan, but the Messenger (peace and blessings be upon him) did not prescribe i'tikaf except in Ramadan. And there is the story of the man who used to recite for his people and would conclude with “Qul huwa Allahu ahad” (Say: He is Allah, the One). Did the Prophet (peace and blessings be upon him) approve of this or not? But is it prescribed?
Yes, it is not prescribed. For this reason, we do not say that it is recommended (mustahabb) for a person to conclude his prayer with “Qul huwa Allahu ahad.” We cannot say that, because the Messenger (peace and blessings be upon him) did not do that. Likewise, the group who asked the Messenger (peace and blessings be upon him) for permission to give charity on behalf of their deceased. He gave them permission to do so, but is it prescribed or not?
Yes, it is not prescribed. It is not prescribed for a person to give charity on behalf of a deceased person. However, if he gives charity, he is not prevented from doing so. Because a man, as in Sahih al-Bukhari, asked the Messenger (peace and blessings be upon him) for permission to give charity on behalf of his mother, and he gave him permission. And he also asked the Prophet (peace and blessings be upon him) for permission to give charity on behalf of the slave of Sa'd ibn 'Ubadah, and he gave him permission. This indicates the ruling on this action. But is it among the prescribed matters?
Yes, in the sense that we say it is recommended (mustahabb) for a person to give charity on behalf of a deceased person? No. But it is among the permissible matters. For this reason, the scholars said: any act of worship (qurbah) that he performs and dedicates its reward to a Muslim benefits him, and it is permissible. We must distinguish between the acts of worship that a person performs and is not blamed for doing, but which came from the Shari'ah, and the acts of worship that are required, which people are asked to perform.