Source that אמונת חכמים applies to the Sages' knowledge besides Halachah

Question

Tons of Jewish responsa (incl. this site) is based on a common belief/premise that the Talmudic Sages knew what they say and that everything they said is true - אמונת חכמים (see this question on this term). While it is difficult to classify all Talmudic statements, I'd like to distinguish between Halachic and factual ones.

• Halachic statements rule Halochos - this thing is Kosher or Mutar or liable, etc. The Sages had the full Heavenly authority to rule the Halochos and we are obligated to follow them, which also includes Hashkafah and Mussar issues (thanks @Micha). This is out of the question.

• Factual statements (this is so and so or this happened so and so) describe the world, its history, and its phenomena. My question is strictly about factual statements, for example "צלופחד הוא המקושש" or "there are billions of stars out there" or "snake is pregnant for 7 years" or "lice create spontaneously".

We can clearly see from the Talmud itself that the Sages did not accept axiomatically each other's opinions and argued strenuously, frequently relying on common non-Jewish knowledge. I know that this remained disputable and many late Rabbis did not accept many Talmudic statements, Rambam didn't canonize it in his principles, and some of the statements were proven as "very hard to reconcile with our empirical knowledge".

But eventually, in common perception, אמונת חכמים was expanded by some to the domain of knowledge also, beyond the realm of Halachah.

I would like to know the earliest source for the claim of אמונת חכמים expands to trusting Sages' knowledge. Did Tannayim or Amorayim themselves say that their knowledge is absolute and indisputable? Were it Gaonim, Rishonim or Achronim?

Answer 1

I like to point out that the Gemara Sotah 4b gives you multiple options on this:

א"ר יצחק בר <רב> יוסף א"ר יוחנן כל אחד ואחד בעצמו שיער והאיכא בן עזאי דלא נסיב איבעית אימא נסיב ופירש הוה ואיבעית אימא מרביה שמיע ליה ואיבעית אימא (תהילים כה) סוד ה' ליראיו

Several rabbis were discussing the minimum time that if a woman was secluded with a man, it's possible they had relations; each gave a different answer.

Said R. Yitzchak bar Yosef in the name of Rabbi Yochanan: eacho f these rabbis' numbers came from their own [intimate] experience. But what about Ben Azai, who never married?! If you want, you could say he married [briefly], then separated; if you want, you could say he heard it from his teacher [R. Akiva]; and if you want, you could apply Psalms 25 -- G-d gave His secret to those who fear Him.

So the Talmud is giving you the option of believing that his study of "pure" Torah mystically imparted him with empirical knowledge that he'd never otherwise know; it also gives you the option to not go there.

By the way that phrase from Psalms was invoked in the vigorous discussion between the late Rabbis Yisrael Shapira and Aharon Lichteinstein zt"l concerning disengagement from Gaza; if I recall correctly Rabbi Lichtenstein felt it was arrogant for any armchair rabbi today to wield it and claim perfect knowledge of military/political outcomes.