4. NO MIXING FIBERS

"Neither shall a garment mingled of linen and woolen come upon thee." -- Leviticus 19:19

The Bible forbids wearing cloth made out of a mix of wool and linen, but other fiber combinations are fine.

The woolly detective: You can hire a "mixed fiber" tester to put your closet under a microscope and find any duplicitous material (since you can't trust the labels).

A baffling taboo: Jacobs says this an unexplained law, but some historians theorize that pagans wore clothes made of wool and linen and this law was a way for the Israelites to set themselves apart from other tribes of the time.

"It is an irrational tradition, but most traditions are irrational. The tradition of blowing out candles is pretty irrational, too."