Study Niddah folio 20B with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
R' Yishmael, son of R' Yosei, explained: It is only R' Ḥanina who is permitted to examine the blood in this fashion, as he is wise, but everyone else is not so wise that they can successfully perform the examination without water.
R' Yoḥanan says: R' Ḥanina’s wisdom causes me not to see blood for a halakhic examination. When I would examine blood and deem it impure, he would deem it pure, and when I would deem it pure, he would deem it impure. Conversely, R' Elazar says: R' Ḥanina’s humility causes me to see blood, as I re
R' Zeira says: The complex nature of the residents of Babylonia causes me not to see blood for a halakhic examination, as I say to myself: Even matters involving the complex nature of people I do not know; can I then claim that I know about matters of blood?
The Talmud asks: Is this to say that the matter of the appearance of blood is dependent on the nature of people, i.e., that it changes in accordance with their nature? But Rabba is an example of someone who knew about the complex nature of the people of Babylonia, and yet he did not know how to dist
The Talmud relates that Ulla happened to come to Pumbedita, where they brought blood before him for an examination, but he would not see it, as he said: If R' Elazar, who was the master of Eretz Yisrael in wisdom, when he would happen to come to the locale of R' Yehuda, he would not see blood, shal