If there is doubt whether water was used for labor, whether it has the required measure, or whether it is impure — is one considered clean, and must one use other water if available?

What is the obligation status of a garment that is open on the sides below but closed above, based on whether its majority is open or closed?

How to Tie Tzitzit

If one is in doubt whether one prayed the obligatory prayer, may one return and pray again?

Rain Prayers

If one is uncertain in the hot season whether one mentioned rain, and uncertainty continues throughout a 30-day period, what is the presumption?

Rain Request (V'Ten Tal U'Matar)

After saying the blessing with rain mention 90 times (corresponding to 30 days × 3 prayers/day) on the first day of Pesach, what presumption applies if one later doubts whether rain was mentioned?

Rain Request (V'Ten Tal U'Matar)

When two ends of tzitzit tear, is it definitively invalid or does it depend on whether the ends come from the same string?

Minimum Length for Valid Tzitzit

May one wear a properly valid tallit (with all four valid tzitzit) in the public domain on Shabbat, whether a small or large tallit?

When to Wear Tzitzit