Rashi

Wool plus linen equals forbidden — but only sheep's wool, only flax linen, and nobody knows why. Inside the labs that check your suit.

Eleven spices, 368 maneh, and one pinch of smoke-raiser that even Alexandria's scientists couldn't crack.

Rav Katina's 6,000-year clock says the year 2239. The Ramban called it non-binding. Maimonides cursed anyone who used it.