Considering Justice in Testimony

Question:
I ask you to please inform me about the sequence of impeaching testimony. For example, if a plaintiff presents evidence for his claim, and then the defendant presents evidence to impeach it, is the testimony for impeaching the impeachment accepted, even if the sequence becomes long? And why is this the case in both situations?

Answer:
The Book and the Sunnah have indicated the consideration of justice in testimony, as in the saying of the Exalted: [Al-Talaq: 2], and His saying (peace and blessings be upon him) : [Al-Baqarah: 282].
It is known that the original state is the innocence of the conscience from rights, so they are not established except by something reliable. There is no doubt that the testimony of open sinners and unknown persons is not permissible to rely upon. Thus, it is clear that justice is necessary in the testimony, those who vouch for it, and those who impeach it or the vouching. For this reason, the scholars have explicitly stated that testimony, vouching, and impeachment are only accepted from those possessing justice and knowledge of the condition of the testimony being vouched for or impeached. From all this, it is known that it is necessary to verify the condition of the testimony upon which the judge relies in his ruling, even if this leads to a sequence until the required justice is reached as much as possible. If that is not feasible, it is permissible for him to rule based on what is most likely to establish the right, even if that leads to administering an oath to the plaintiff along with his testimony.
As for separating the witnesses when giving testimony, it should be done when necessary, out of fear of their collusion in lying.