Testifying to the character of a stranger before the judge

Question:
A questioner says: I left a man for a short time to go to the judge alone, and I did not know that you were a man before, and that you were exposed to the decision, but I was angry at a place before the judge, and I tried to know how to get out of it, and also that the judge would approve of something, and it happened

Answer:
This is a mistake, testifying to a man whom you do not know. But if you said, "I know nothing against him," that is good. If you said, "I know nothing against him," you have spoken the truth in that, if you have no knowledge of his conduct and know nothing about him. But if you said that he is vouched for, that he is good, and that he is a righteous man, and you do not know him, this is a mistake and not permissible. Allah the Exalted said: It is necessary that testimony be based on knowledge, so testify based on knowledge.