Imam Maalik مالك بن أنس بن مالك بن أبي عامر · The Book on Sacrifices

"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."

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)."

"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) said: "The best of Udhiyah (sacrifice) is a ram, and the best (burial) shroud is the Hullah."