Section: If he bequeaths a share of an heir, there are two views regarding this. One is that the bequest is valid, and this is considered the same as a bequest of the equivalent of his share. This is the position of Malik, the people of Medina, al-Lu'lu'i, the people of Basra, Ibn Abi Layla, Zufar, and Dawud. The second view is that the bequest is not valid; this is what the Qadi mentioned, and it is the position of the companions of al-Shafi'i, Abu Hanifa, and his two companions. This is because he has bequeathed something that is a right of the son, so it is not valid, just as if he had said, "My son's house," or "What my son takes." The reasoning for the first view is that it is possible to validate his bequest by interpreting his wording according to its metaphorical sense, so it becomes valid, just as if he had divorced using a metonymic expression or emancipated. The proof for the possibility of validation is that it is possible to posit an ellipsis of the genitive (idafa) and to let the genitive noun (mudaf ilayh) take its place, meaning: "an equivalent to the share of my heir." Also, because if he bequeathed his entire wealth, it would be valid, even if that involved the bequest of the shares of all his heirs.

Section: If he said: "I have bequeathed to you double the share of my son," he is entitled to two equivalents of his share. This is what al-Shafi'i stated. Abu Ubayda al-Qasim ibn Sallam said: "The double (di'f) is the equivalent (mithl)." He provided as evidence the saying of Allah the Exalted: "The punishment shall be doubled (di'fayn) for her," (6) meaning two equivalents, and His saying: "It brings forth its fruit two-fold (di'fayn)," (7) meaning two equivalents. If the double (di'fayn) is two equivalents, then the singular is an equivalent. Our position is that the double (di'f) is two equivalents, based on the evidence of the saying of Allah the Exalted: "Then We would have made you taste a double (di'f) of life and a double (di'f) of death," (8) and He said: "For those is the reward of the double (di'f) for what they did," (9) and He said: "And whatever you give in Zakat, seeking the countenance of Allah, those are the ones who are multipliers (al-mud'ifun)," (10). It is reported from Umar that he doubled (ad'afa) the Zakat on the Christians of Banu Taghlib, taking ten from every two hundred. He said to Hudhayfah and Uthman ibn Hunayf: "Perhaps you have burdened the land with what it cannot bear?" Uthman replied: "If..."