Babylonian Talmud, Shabbat 67b
תלמוד בבלי מסכת שבת דף סז עמוד ב
אמר רב זוטרא: האי מאן דמיכסי שרגא דמשחא ומגלי נפטא - קעבר משום בל תשחית.
Rav Zutra says, One who covers an oil lamp, or uncovers a naphtha lamp has violated ba'al taschit. (note: ba'al taschit refers to the Torah's prohibition on wasteful or pointless destruction of property or resources)

Suggested Discussion Questions:

1. What are modern parallels to covering an oil lamp or uncovering a lamp? What is the parallel to electricity?

2. What are various denominations' reactions to the belief that leaving lights on during shabbat is wasteful rather than halachic?

Time Period: Rabbinic (Maccabees through the Talmud)