Bal tashkhit ("do not destroy") is a basic ethical principle in Jewish law.
The principle is rooted in the Biblical law of Deuteronomy 20:19–20. In the Bible, the command is said in the context of wartime and forbids the cutting down of fruit trees in order to assist in a siege.
In early rabbinic law however, the bal tashkhit principle in understood to include other forms of senseless damage or waste. For instance, the Babylonian Talmud applies the principle to prevent the wasting of lamp oil, the tearing of clothing, the chopping up of furniture for firewood, or the killing of animals.[1] In all cases, bal tashkhit is invoked only for destruction that is deemed unnecessary. Destruction is explicitly condoned when the cause or need is adequate.
In contemporary Jewish ethics on Judaism and ecology, advocates often point to bal tashkhit as an environmental principle. A few scholars have questioned or qualified the application of bal tashkhit to environmental problems, though its relevance to waste reduction remains well-accepted.