Reference of Measurements in Halacha: Difference between revisions

# According to Rav Chaim Noeh, the Kezayit for Deoritta measures (eating Matzah) and Bracha Achrona is 25.6 cc (in volume). Nonetheless because food stuck in between one's teeth doesn't count towards a Kezayit eaten one should make sure to have 28.8 cc. Regarding a Kezayit for derabbanan measures (eating maror) the kezayit is 17.3 cc. <ref>Shiurei Torah (by Rav Chaim Noeh, Siman 3 Seif 13 pg 191) </ref> The Chazon Ish’s opinion is that the Kezayit is 33.3 grams (1.3 oz). <ref>Vezot HaBracha (pg 6) </ref>

# The minhag of the world and many other authorities is to follow Rav Chaim Noeh’s opinion. <Ref> Vezot HaBracha (pg 6, Birur 1, pg 221) in name of Rav Elyashiv and Rav Shlomo Zalman that one may follow Rav Chaim Noeh’s opinion and there’s no need to be strict for the Chazon Ish’s opinion. Vezot HaBracha also mentions that such is the minhag of the world. </ref>

==KeBaytzah==

# According to Rav Chaim Noeh, the KeBaytzah is 55cc and according to the Chazon Ish is 100cc. <ref>Vezot HaBracha pg 6 </ref>

==Amah, Tefach, Etzbah==

# According to Rav Moshe Feinstein, the Amah is 21.25 inches (53.98 centimeters), the Tefach is 3.54 inches (9.00 centimeters), and the Etzbah is 0.89 inches (2.25 centimeters). <ref> Sh”t Igrot Moshe O”C 1:136. writes that the Amah is 21.25 inches and one can be strict to hold that it is 23 inches. </ref>

==Reviyit==

# A Reviyit is a Kebaytzah and a half. <Ref>Mishna Brurah 486:1 </ref> Therefore, according to Rav Chaim Noeh, the Reviyit is 86 grams (3 oz) and according to the Chazon Ish the Reviyit is 150 grams (5.3 oz). <ref>Vezot HaBracha (pg 6) </ref>

==Practical applications==

# If one ate between a third and a half a KeBaytzah one should not make a Bracha achrona because of safek Brachot. Therefore, one should have less than a third and not make a Bracha achrona or more than a half and make a Bracha achrona. <Ref> Mishna Brurah 486:1 </ref>