The Udhiyah: Its Conditions and Etiquette

The Shaykh : As for the udhiyah, the udhiyah is a confirmed recommended practice (sunnah muakkadah). It is a confirmed recommended practice that one who is able to afford it should not leave off, to the extent that some scholars said: it is obligatory (wajib) for one who is able, due to the command of the Prophet (peace and blessings be upon him) regarding it and his doing of it. It is disliked (makruh) for one who is able to leave off the udhiyah; rather, he should sacrifice on behalf of himself and his household. The udhiyah is not valid except with three conditions:
The first: that the udhiyah be from the livestock of grazing (buhimat al-an'am), which are camels, cattle, and sheep. If a person sacrificed with a horse, does it suffice or not? It does not suffice. If he sacrificed with a gazelle, it does not suffice. It must be from the livestock of grazing, which are: camels, cattle, and sheep, whether goats or sheep.
The second condition: that it has reached the obligatory age, which is six months for sheep, one year for goats, two years for cattle, and five years for camels, and anything less than that does not suffice, due to the saying of the Prophet (peace and blessings be upon him and his family): .
The third condition: that it be free from defects that prevent sufficiency, which are those the Prophet (peace and blessings be upon him and his family) referred to in his saying: . "Al-'ajifa" means: the emaciated one that has no marrow. How many conditions? Three. The time remains. It must be within the time specified by the Shari'ah, which is from the 'Id prayer until the setting of the sun on the last day of the days of Tashriq. So whoever slaughters before the prayer, it does not suffice, and it is obligatory (wajib) upon him to slaughter a replacement for it. That is to say, if a person, when the morning of the day of 'Id arrives and the sun rises, says: "I want to slaughter the udhiyah so that when I return from the prayer, I find the meat cooked," and he slaughters it, we say: this does not suffice. Your sheep is a sheep for meat. If you wish, you may sell the meat for its value; if you wish, you may give it as a gift; if you wish, you may give it in charity; if you wish, you may eat it. The important thing is that it is a sheep for meat. And it is obligatory (wajib) upon him to slaughter a similar one. Obligatory (wajib) upon him to slaughter a similar one after the prayer. Until when? Until the last day of the days of Tashriq. When the sun sets on the third day of the days of Tashriq, the time for the udhiyah ends. So how many days are there? Four days. And when the tenth of Dhul-Hijjah enters and a person has intended the udhiyah, he does not take anything from his hair, his skin, or his nails until he sacrifices. Three things: the hair, and the second? The nails. And the third? The skin. What is the skin? The skin. Someone might say: How does a person take from his skin? We say: Yes, he takes. There are some people who have cracks in their feet, and you find them plucking them. This is not permissible (la yajuz) for one who intends to sacrifice.