On this daf, the Mishna tells us that it is permitted to wash the child before and after his bris.
It then tells us that one may   sprinkle water on him with one’s hands but not with a vessel.
Although it is not normally permitted to wash one’s entire body in warm water on shabbos (a subject for its own discussion,) this prohibition is waived, presumably due to pikuach nefesh considerations.
Rabbi Elazar ben Azaria goes further and permits one to wash the child again on the third day, if it falls on shabbos, because the third day is usually the hardest time during recovery.
The Gemara notes an apparent contradiction in the words of the Tana Kama (first opinion.)
One the one hand, we are told that it is permitted to wash the child properly, but we are then told that one may only sprinkle water on him with one’s hands.
The Amoraim debate how to reconcile this contradiction.
Rav Yehuda and Rabbah bar Avuha understand that the second part of the Mishna is coming to explain the first part- the washing permitted in the first part refers to sprinkling with one’s hand only.
Rava, on the other hand, is unconvinced.
He believes that the word “washing” referred to in the first part is precise, and refers to a proper wash, not just sprinkling.
As such, he interprets the Tana Kama’s words as permitting normal washing with warm water before and after the bris, but only sprinkling with the hand on the third day.
According to this interpretation, Rabbi Elazar ben Azaria then comes and permit regular washing even on the third day.
A Beraisa is then brought which supports Rava’s interpretation.         
The Gemara then relates that this question was brought to Rava and he ruled according to his view, permitting regular washing of the infant.
Rava became ill, and he blamed his illness on himself for going against the view of his seniors, Rav Yehuda and Rabbah bar Avuha, who held that the Mishna only permitted sprinkling water with the hands.
This story needs some explanation: Is a later Amora really not allowed to disagree with an earlier one?  In general, the golden rule is that Amoraim(sages of the Talmud) may not disagree with Tannaim (sages of the Mishna), but the entire shas is filled with cases where later Tannaim disagree with earlier Tannaim and later Amoraim disagree with earlier ones! Moreover, under certain conditions when this happens, the rule is even that הלכה כבתראי, the law follows the later authority!
Not only that, but there are many cases of Rabbi’s who have reached an independent status in  their own learning, disagreeing with their own Rabbis (Reish Lakish being one of the most common examples in his regular debates with Rabbi Yochanan!)
Furthermore, is this not a transgression of the prohibition of superstitious behaviour, namely basing one’s actions on logically unrelated signs with no evidence of cause and effect (see Sanhedrin 66a.)
It seems clear from an earlier analysis we did (at least according to Rambam,)  that the dictum אם ראשונים כמלאכים אנו כבני אדם אם ראשונים כבני אדם אנו כחמורים  (If the early one’s were like angels, we are like people, if they were like people, we are like donkeys- Shabbos 112,) is not meant to be a halachik statement preventing a later authority from differing with an earlier one, but rather a statement about a general trend.
We have discussed this in a previous post, and also noted how in a different sugya (Brachos 20), Rav Papa asks Abaya why it is that the earlier generations merited to experience miracles, and their generation did not.
Rav Papa pointed out that it cannot be because they knew more Torah, as Rav Yehuda’s generation were focused on the part of the Talmud that focusses on damages, and they were focused on all 6 sections of the Talmud.
It also could not be that they understood it better, as Rav Yehuda expressed great difficulty with a certain Mishna while they were able to expand on it with ease.
Yet Rav Yehuda only needed to remove his shoe for rain to come, and their generation could daven all day and nothing happened!
Abaya responded that Rav Yehuda’s generation sacrificed themselves to sanctify Hashem’s name (did risky things to preserve the honor of the Torah) and their generation did not.
It seems from there that the superiority of the earlier generations lies NOT in their breadth of knowledge, nor in their greater analytical ability, but rather in their מסירות נפש (self-sacrifice.)
It  also is not likely to be coincidental that Rava was of the same generation of Abaya, and had disagreed with a ruling of Rav Yehuda, the very Amora that Abaya had praised for his superior self-sacrifice, but NOT for his superior learning.(though see our earlier post on daf 112 where we brought the view of the Rosh that  the rule of הלכתא כבתראי  applied only from Abaya and Rava onwards, and not to the period of Rav Yehuda!)
Perhaps Rava was not concerned so much about the fact that he had disagreed with a senior of his, but that he had disagreed with TWO of his seniors, with none of his own colleagues supporting him, possibly without being sure enough of his own position.
It is one thing to have the authority, or even the knowledge, to disagree with one’s seniors, and to use that right where necessary.
It is another thing completely to do this lightly, without being completely sure that it is the correct thing to do.
When disagreeing with a group of scholars who are both his seniors and more numerous than himself, the question is not only whether one MAY do so, but whether one should.
Perhaps Rava, while aware of his own status and ability to disagree, once faced with his illness , had second thoughts, and was modest enough to look at things from scratch and consider that maybe  his more numerous and older antagonists were indeed correct.
The continuation of the sugya shows that this was indeed the case.
Rava’s colleagues expressed surprise at his recanting, pointing to the fact that a Beraita had been quoted supporting his interpretation of the Mishna.
It is likely that Rava too was aware of that Beraita and took it into account when making his decision.
Yet even with what appears to be good evidence against one’s seniors, one needs to have a very strong degree of certainty that the evidence is irrefutable.
Rava replied to his colleagues that even though the Beraita did indeed support him,  he  saw that the wording of the more authoritative Mishna supported Rav Yehuda and Rabbah bar Avuha better, and therefore had serious reason to reconsider his ruling.
We see from this that though one should  have very strong evidence before disagreeing with a plurality of those who came before you,  once one has that evidence,  an event which could be seen as a sign that one was wrong should not on its own be a reason to recant- that could even  be a transgression of the prohibition of superstitious behaviour!
At most, it should serve as a sign that one should look again at the evidence and be open to the possibility that he was wrong.
As Chazal said, though admittedly in a slightly different context  אע”פ שאין נחש יש סימן  (even though we do not base our actions on superstitious interpretations of events that happen, one can see them as a sign! (Chullin 95b)
These posts are intended to raise issues and stimulate further research and discussion on contemporary topics related to the daf. They are not intended as psak halacha.