Question: Is it a condition, in the case of sacrificial animals, that the slaughter take place at a time when slaughter is permitted?
Answer: This is not a condition for the animal to be lawful to eat, but it is a condition for it to count as an udhiyah (Eid sacrifice).
His statement: “He says: ‘In the name of Allah; Allah is Most Great.’” If he were to say, “In the name of the Most Merciful,” or “In the name of the Originator of the heavens and the earth,” or “In the name of the All-Creating, All-Knowing,” would this suffice in place of “In the name of Allah”? The answer is that some scholars held that it does suffice if he ascribes the word “name” to one to whom it can apply only to Allah. It is then equivalent to ascribing it to the Divine Name, and there is no difference, since it is truly a mention of Allah’s name. But if he says, “In the name of the Most Kind, the Most Merciful,” it does not suffice, because this description may apply to other than Allah. Allah Almighty said in describing the Prophet: “To the believers he is most kind and merciful.” [al-Tawbah 9:182] If he says, “In Your name, O Allah, I slaughter this animal,” it suffices, because it is equivalent to saying, “In the name of Allah.” The evidence for saying “Allah is Most Great” is the hadith of Anas, recorded by al-Bukhari and Muslim, that the Prophet, may Allah’s peace and blessings be upon him, mentioned Allah’s name and proclaimed His greatness. (1)
Should one invoke blessings upon the Prophet, may Allah’s peace and blessings be upon him, in this situation? The answer is that one should not invoke blessings upon the Prophet, may Allah’s peace and blessings be upon him. The reasoning is as follows:
First: this has not been reported, and worshipping Allah through what has not been prescribed is an innovation.
Second: it could later become a means leading to the name of the Messenger, may Allah’s peace and blessings be upon him, being mentioned over the sacrificial animal. For this reason, the scholars disliked invoking blessings upon the Prophet, may Allah’s peace and blessings be upon him, over an animal being slaughtered.