What is the ruling on concealing testimony

Question:
I have some rights owed to me by others, and we reached the court. There are some of our brothers who know everything between us, and I asked them to testify, but unfortunately they did not testify?

Answer:
We ask Allah for guidance for us and for them. Your Lord (Exalted and Majestic is He) said: [al-Baqarah:283] If they conceal it, and they know it, then sin is upon them, and it is not permissible for them to do so. However, if they have doubt, there is no blame on them. If they do not have certainty, it is not permissible for them to testify. If they are not certain, it is not permissible for them to show favoritism for the sake of your right over them, or because you are their companion. No.
So testimony is a matter of great gravity. If they have knowledge, it is obligatory for them to perform it, and it is forbidden for them to conceal it. As for testifying just because you are their companion based on doubt or suspicion, that is not permissible. This is like what some Bedouins do, and some city dwellers as well. As long as he is his friend, he says: You are my friend, and you know that I am truthful, testify for me. This is not permissible. Even if you were his brother, and even if you were truthful, he does not testify except with clear evidence. Otherwise, false testimony is among the ugliest of major sins, we seek refuge in Allah.
So a person must testify to something he knows. As for saying: You know me, and I am, praise be to Allah, truthful, and I, I, I bought such and such from so-and-so, or sold him such and such, testify for me. This is not permissible. Even if he were from the Companions, it is not permissible to testify for him without right.

Question: Was a curse reported for the one who conceals testimony?

Answer: I do not recall, but the text of the Qur'an is sufficient. The text of the Qur'an is sufficient: [al-Baqarah:283] We ask Allah for safety. As for the curse, I do not recall anything in this regard.