Since excellence in slaughter is required—out of mercy for the animal and in order to end its life swiftly—the Prophet placed his noble foot on the sides of their necks so that they would not thrash about during the slaughter. Were they to struggle, the process would be prolonged and would amount to tormenting them, and Allah is ever-merciful to His creatures.

Lessons drawn from the hadith:

1. The legitimacy of the udḥiyah, about which the Muslims have reached a consensus. Shaykh al-Islām said: “The udḥiyah is better than giving its price in charity; therefore, when a person has wealth with which he wishes to seek closeness to Allah, it is proper for him to offer a sacrifice.”
2. It is preferable that the sacrificial animal be of the same type the Prophet—peace and blessings be upon him—chose, for he may have selected that description for a particular wisdom; Allah knows best.
3. Whoever is skilled at slaughtering should perform it himself, for slaughtering an animal intended as an act of worship is a distinguished form of devotion.
4. At the moment of slaughter one should say: “In the name of Allah; Allah is the Greatest.” The relevance of this wording here is self-evident.
5. He should place his foot on the side of the animal so that it does not struggle, enabling him to hasten its death and spare it distress.
6. When slaughtering sheep, it is preferable to lie the animal on its left side, for that is easier.

Points taken from the words of Shaykh al-Islām Ibn Taymiyyah:
First: It is permissible to offer an udḥiyah on behalf of a deceased person, just as one may perform Hajj or give charity for him.
Second: One should give a third of the meat in charity and a third as gifts; if he eats more than a third, gives away more, or cooks it and invites people to partake, all of that is permissible.
Third: If a person sacrifices one sheep on behalf of himself and his household, it suffices according to the sounder of the two scholarly opinions— the position of Mālik and Aḥmad—because the Companions used to do so.