What is meant by the unknown identity (jahl al-'ayn)? Is it doubt about his existence in the first place?

The questioner : You mentioned that a narrator of unknown identity (majhul al-'ayn) is one where, if two narrators report from him, and neither of them is at the level of being relied upon and accepted, but only at the level of corroborating evidence, then they do not elevate the ruling from unknown identity to unknown condition; rather, he remains of unknown identity. You also mentioned, from the perspective of the son, that if his son or grandson reports from him, he also remains of unknown identity, and this son is like another trustworthy man. The issue of kinship is not, I mean, mentioned in this difficulty that has appeared to me, and I want to inquire of you and clarify from you, may Allah bless you. It is that the one of unknown condition has a known identity, but his condition is unknown. And the one of unknown identity, as I understand it, is one whose existence is doubted in the first place: is he existent or not? The one of unknown identity is one whose self is unknown. So, if the one reporting from him is his son, and we know that a son does not exist without a father, and a son must have a father, then the existence of the son is proof that he had a father. So this is proof of the existence of the identity, not unknownness in the identity. Is this statement correct, may Allah preserve you?

The Shaykh : I have not come across such a statement, nor have I thought about it. And if it is permissible for me to answer immediately, I do not see that, I mean, the previous statement is that there is a difference between the narrator being the son or the narrator being other than the son, as long as both are trustworthy. This is from one aspect. From another aspect, it does not occur to me when they use this term, unknown identity, that it means he is considered non-existent, as long as the one reporting from him is trustworthy. I do not think that is their intention when they say he is of unknown identity. If a trustworthy man reports from him, he is like non-existent. But from the hadith perspective, they agreed on this terminology. Here my question arises: Is it true, in what has appeared to you from your study of this noble science, that they rule on him as if he is non-existent, I mean, even though the one reporting from him is trustworthy?

The questioner : What led me to this was when I saw al-Hafiz in al-Taqrib that, if his son, grandson, or nephew reports from him, in most of the biographies I have encountered, and I am in the process of writing a commentary on al-Taqrib, and I have reached, praise be to Allah, one-third of it.The Shaykh : What Allah willed.

The questioner : Up to the end of the letter Sin in it, I saw that most of what is said about him is "accepted," and in two biographies, as I recall, he said about him "unknown."

The Shaykh : This, may Allah bless you, would have been consistent if we had not both seen that he also says "accepted" in cases where the one reporting from him is not the son, nor the grandson, nor something similar. This would have been consistent. This is first. And second, you now mentioned that this rule that has settled in your mind from following him in his practice has been contradicted in two biographies. So these two biographies, like many, many other biographies, according to the methodology he established in the introduction of his al-Taqrib, he deviated from this methodology in dozens of biographies where he says in each of them "accepted," and his right is to say in them "unknown," because the one reporting from him is only one.

The questioner : So, my Shaykh, the issue of unknown identity does not mean doubt about his existence.

The Shaykh : No, no, it does not mean doubt about his existence.

The questioner : May Allah preserve you.

The Shaykh : And you as well.

The questioner : Likewise.