Ruling on slaughtering sick sheep with the intention of depriving Satan of them, without eating them

The questioner: Some people who own sheep, when one of their sheep or goats falls ill and they despair of its recovery, slaughter it and say, “We are depriving Satan of it,” and they slaughter it but do not eat it. What is your opinion on this?The Shaykh: Our view is that if a person has a sheep, a camel, or a cow, and he despairs of it if it is sick, there is no harm in killing it and leaving it. But if it is not sick, it is obligatory for him to slaughter it and give it in charity.And my saying: By “not sick,” I mean, for example, if it falls from a height and breaks its neck, and he hastens to slaughter it. In this case, he must slaughter it according to the lawful method of slaughter. As for the statement, “We do not leave it for Satan,” this is a known practice among the common people, but I do not know of any basis for it.