Nidah Chart #2
Chart for Nidah Daf 17b
BLOOD FOUND IN THE "PROZDOR"
BLOOD FOUND ON ROOF, FROM LUL AND INWARDS (1)
BLOOD FOUND ON ROOF, FROM LUL AND OUTWARDS (2)
BLOOD FOUND ON FLOOR (3)
|1||RAMI BAR SHMUEL,
RAV YITZCHAK BREI D'RAV YEHUDAH
|2||RAV HUNA||Tamei||Safek||Tamei (4)|
(1) Blood gets here more easily from the Aliyah than from the Mekor (TOSFOS DH Min ha'Lul). Nevertheless, we consider the blood found here to be Tamei because "Chezkaso Min ha'Mekor" (Mishnah) -- that is, there is more blood in the Mekor than in the Aliyah, and we therefore apply the principle of "Rov" (18a, Rashi DH Ha d'Amrinan).
(2) Blood gets here much more easily from the Aliyah than from the Mekor.
(3) Blood gets here more easily from the Mekor than from the Aliyah.
(4) Although Rav Huna does not discuss this case explicitly, it can be inferred that this blood is certainly Tamei from the fact that the blood found on the roof, on the inner side of the Lul (2-A in Chart) is Tamei. (See TOSFOS 18a, DH Kan.)
(5) This is according to RASHI (18a, DH u'Meshaninan). However, TOSFOS (18a, DH Kan) disagrees and asserts that even Abaye would consider such blood to be Tamei.