Pesahim 109 - Measuring a Mikveh and a Winecup
Rabbi Richard Hidary
Pesahim 109 How big is a revi’it? Rav Hisda’s thesis: Reviit log = 2 x 2 x 2.7 fingerbreadths = 10.8 cubic fingerbreadths Proof from Baraita: 40 seah = 3 cubic amot 1 Seah = 6 kav = 24 log = 96 revi’it log volume measurements 40 seah = 3840 revi’it log 1 Amah = 6 tefah = 24 fingerbreadths distance measurements 3 cubit amot = 3 x 243fingerbreadths = 41,472 cubic fingerbreadths 3,840 revi’it log = 41,472 cubic fingerbreadths 1 revi’it log = 10.8 cubic fingerbreadths 1 amah = 19.2 inches 40 seah = 3 cubic amot = 3 x 19.23 inches = 21,234 cubic inches = 92 gallons Revi’it = 92 gallons / 3840 = 11,776 fluid oz / 3840 = 3.06 oz