Testimony to the truth is only valid based on knowledge

Two men went to greet one of the judges. When they entered, they found a man with him claiming to have a piece of land and wanting to obtain a deed for it. When these two men entered, the judge knew them and knew that they had no connection to the matter and that they had come only to greet the judge,So he said: these two testified, so the judge wrote it down and they testified, and the matter was concluded, and the man took it. The town where the judge is located is 500 kilometers away from the town where the land is located. What is the ruling on the testimony of these two witnesses?

By Allah! You must know that testimony requires knowledge: [Surah al-Zukhruf: 86] The witness must know that one who testifies to the truth must have knowledge,Meaning now: If two men were before you, and one claimed against the other one hundred riyals, and the second denied it. I know that the claimant is a truthful man who has religion, trustworthiness, and scrupulousness, and that the other, the denier, is a man who is lax in his religion and does not care to deny what is obligatory upon him. Now I know that the claimant is correct, is that not so? Do I have the right to testify? I know that the truth is with the claimant because he is a man of scrupulousness and religion, and he cannot claim what is not his. But do I have the right to testify to this right which I believe to be true while I do not know it? I do not testify,Therefore: It is not permissible for any person to testify except to what he knows to be the truth. Even if he knows that it is the truth based on the claimant's circumstances, it is not permissible for him to testify, unless he knows the case himself.
In any case, I have now informed you. It is not permissible for witnesses to testify except to what they know directly themselves, and it is not permissible for the judge to write down their testimony while he knows that they did not witness the case.