Their statement in the books of terminology: "Authentic, but not something about which certainty is established" — what is its meaning? And what is its correctness?

The questioner : Shaykh, in the books of some of the people of hadith terminology, when they mention the definition of the authentic hadith, they say: "Authentic, but not something about which certainty is established"; so what is the meaning of this phrase? And how correct is it?

The Shaykh : The intended meaning is clear. The authentic hadith, in reality, indicates the preponderance of probability regarding its establishment. So any hadith narrated by a trustworthy person from a trustworthy person until it reaches the Prophet (peace and blessings be upon him) — anyone below the Prophet (peace and blessings be upon him) may commit a slip or an error, with the exception of the Messenger (peace be upon him), the one who conveys from the Lord of the Worlds. Because of this possibility, which no sane person can do except to accept as a possibility, every narrator after the Messenger (peace be upon him) may have slipped in narrating this hadith. And because this is a possibility, the narration of an authentic hadith does not provide certainty and absolute conviction, but rather it provides the preponderance of probability. And what is predominantly probable to be authentic may possibly be inauthentic, but such a possibility is usually not given weight; because the legal rulings that are issued through the ijtihad of the imams are also based on the preponderance of probability. So if reliance on what is built on the preponderance of probability were discarded, the legal rulings would be suspended, including the narration of authentic hadiths; because no one absolutely says that the solitary, rare hadith from a trustworthy, upright, and precise narrator provides certainty; because that would mean he is infallible from falling into error, and no Muslim says that.
But if the solitary, rare hadith comes with a correct chain according to the terminology of the hadith scholars, and it is possible that in reality it is inauthentic, that does not mean it is not permissible to rely on it because of that possibility; because the mentioned possibility is only a theoretical matter, and the preponderance of probability is that it is authentic, and that the Prophet (peace and blessings be upon him) said that hadith. So what is the case, the original ruling is that it is to be used as evidence, unless the opposite is established; that is: it is established that one of the narrators made a mistake in this hadith. At that time, the matter flips from being an authentic hadith to being an inauthentic hadith. In the first case, it was obligatory to act upon it; in the second case, it is not permissible to act upon it; because acting is obligatory only with the ruling that is the preponderance of probability.
Some scholars exclude from the rule that an authentic hadith may possibly be inauthentic in reality — and this, as we confirmed earlier, is merely a theoretical possibility, and the obligation is to use it as evidence —, nevertheless, some scholars say: This authentic hadith, which may possibly be inauthentic in reality, may be accompanied by circumstances that remove the previous possibility, and the researcher becomes certain that its establishment is something about which certainty is established. And among the famous examples of that are the hadiths that came in "the two Sahihs" and were received by the community with acceptance, and nothing from them was criticized by the memorizers. This type of authentic hadiths provides certainty and conviction due to the consensus of the community on accepting them, despite their disagreement in acting upon them.
This is the detailed answer to the previous question.
Yes.

The questioner : ... .

The Shaykh : Wait a moment.
Yes.