while Imam al-Shāfiʿī deems it merely recommended.
Al-Ghazālī remarks: “The reports on this point reach the level of mass transmission, and there is unanimous agreement on its legitimacy.”
10 – Along with saying “In the name of Allah,” it is prescribed to add at the moment of slaughter, “Allah is greatest,” in view of His words: “Thus We have subjected them to you so that you may magnify Allah for guiding you” (22:37). Ibn al-Mundhir said: “It is firmly established that the Prophet ﷺ used to say it.” Among the relevant reports is the present ḥadith in which he said, “In the name of Allah; Allah is greatest.” The scholars unanimously hold that pronouncing the takbīr at slaughter is recommended, not obligatory.
11 – It is recommended for the one offering the uḍḥiyah to perform the slaughter himself, provided he is skilled at it, because slaughtering is an act of worship and a means of drawing near to Allah. Al-Iqnāʿ states: “If he slaughters it with his own hand, that is unquestionably superior,” for in this he imitates the Prophet ﷺ, who with his own hand sacrificed sixty-three camels from his hady and likewise slaughtered his uḍḥiyah. The scholars are agreed that for the offerer—whether of an uḍḥiyah or a hady—to slaughter his own animal is recommended, not mandatory.
12 – If he does not carry out the slaughter himself, it is preferable that he be present when it is done. The Prophet ﷺ said to Fāṭimah: “Attend your sacrificial animal; you will be forgiven with the first drop of its blood” (reported by al-Ḥākim 4/247). In another report from Ibn ʿAbbās the Prophet ﷺ said: “Attend them when you slaughter, for you will be forgiven at the first drop of their blood.”
13 – It is recommended to slaughter with a sharp instrument. The Prophet ﷺ said, “Sharpen it on a stone,” and a keen blade brings relief to the animal by hastening the departure of its soul—this is excellence in slaughter and mercy toward it. He ﷺ also said: “When you slaughter, do it well: let each of you sharpen his blade and spare the animal suffering” (Muslim 1955).