His statement, “the one-eyed, the emaciated, the lame, and the sick”: these four were explicitly mentioned by the Prophet, peace and blessings be upon him. He was asked, “What should be avoided in sacrificial animals?” He replied, “Four,” and indicated with his fingers: “the one-eyed...” (1) However, the Prophet, peace and blessings be upon him, qualified this by saying, “the one-eyed animal whose defect is plainly evident” (2): that is, one whose eye protrudes or is sunken. Is there, then, a one-eyed animal whose defect is not evident?
The answer is yes. Suppose it cannot see with one eye, yet when you look at that eye, you would think it sound. Such an animal is one-eyed, but its defect is not apparent, and it is therefore valid. Nevertheless, an animal free of this defect is preferable. The wisdom behind this is, on the one hand, its disfigured appearance and, on the other, its reduced intake of feed. Its disfigured appearance is evident; and its intake of feed is reduced because it sees from only one side, so its ability to take in food is diminished. It may graze on one side of a tree while failing to graze on the other. By stronger analogy, the blind animal falls under the same ruling, for if the loss of one eye prevents validity, then the loss of both eyes does so all the more.
Some scholars who favor discretionary reasoning held that a blind animal is valid, even though a one-eyed animal is not. They argued that the one-eyed animal is prohibited only because its vision is deficient and it grazes from one side alone; whereas, its owner will bring feed to the blind animal, so it suffers no deficiency and is therefore like an animal that can see.
This is a peculiar analogy. One should ask: is this blind animal defective or not defective?