That the Messenger of Allah (ﷺ) said: "A human does no action from the actions on the day of Nahr more beloved to Allah then spilling blood (of sacrificial animals). On the Day of Judgement, it will appear with its horns, and hair, and hooves, and indeed the blood will be accepted by Allah from where it is received before it even falls upon earth, so let your heart delight in it."
"The Messenger of Allah (ﷺ) slaughtered two horned male sheep which were mostly white. He slaughtered them with his hand and mentioned Allah's Name, and he said 'Allahu Akbar', and put his foot on their side."
That 'Ali used to slaughter two male sheep, one for the Prophet (ﷺ) and the other for himself. When this was mentioned to him, he said: "He ordered me to" - meaning the Prophet (ﷺ) - "So I will never leave it."
"The Messenger of Allah (ﷺ) slaughtered a horned male ram of fine pedigree, (around) his mouth was black, and his legs were black, and (around) his eyes was black.
A Marfu' narration (from the Prophet (ﷺ)), saying: "A crippled animal whose limp is obvious is not to be slaughtered as sacrifice, nor an animal with a bad eye whose blindness is obvious, nor a sick animal whose sickness is obvious, nor an emaciated animal that has no marrow (in its bones)."
"The Messenger of Allah (ﷺ) ordered that we check the eyes and ears, and not to slaughter the Muqabalah, nor the Mudabarah, nor the Sharqa', nor the Kharqa'"
"The Muqabalah is the one whose ears have been severed, the Mudabarah is the one with the sides of its ears cut off, and the Sharqa' is one with its ears split, and the Khurqa' is the one whose ears have a hole pierced through them."
"I brought a Jadha' sheep to Al-Madinah (for sale) but it remained with me. I saw Abu Hurairah and I asked him about it, so he said: 'I heard the Messenger of Allah (ﷺ) saying: "The best male" - or - "female Udhiyah is that from the Jadha' sheep." He said: "So the people took note of that (they became interested in buying)."
That the Messenger of Allah (ﷺ) gave him sheep to distribute among his Companions as a sacrifice. "There remained a young male kid or a young billy goat, so I mentioned that to the Messenger of Allah (ﷺ) and he said: 'Sacrifice it for yourself.'" Waki' said: "The Jadha' among sheep is seven or six months."