Delivering testimony means establishing it before the judge. Once a person has undertaken testimony, he must testify, for Allah, Exalted is He, says:
“Do not conceal testimony, for whoever conceals it—his heart is indeed sinful.” [al-Baqarah 2:283]
Allah has thus declared the heart of the person who conceals testimony to be sinful, and He ascribed the sin to the heart because no one knows of his testimony except Allah, Exalted is He; for he may deny it. Since the denial of testimony—while he knows that he is a witness—takes place in the heart, Allah says: “For whoever conceals it—his heart is indeed sinful.” Since testimony is preserved in the heart, and concealment takes place only in the heart, Allah, Most High, ascribed the sin to the heart, which is where the testimony is retained.
Some scholars have said that delivering testimony is a collective obligation. The practical consequence of this disagreement arises when ten people are called to witness a matter and undertake the testimony, and one of the litigants brings his dispute with his opponent before the judge. He then goes to two of the ten and says, “I have brought my case against my opponent before the court, so come with me to deliver the testimony.” According to the author’s view, those two are individually required to go with him. According to the view that it is a collective obligation, they are not individually required, for they may say to him, “Go to the other eight and ask two of them.”
But the correct view is that of the author: once a person is summoned to deliver testimony, he is individually obliged to testify. For if we were to allow him to refer the testimony to others, he might go to two of the eight, and they would say, “There are six others remaining.” He would then go to two more, who would say, “There are four remaining.” Then he would go to another two, who would say, “There are two remaining.” Finally, he would go to the last two, and they would say, “Why have you singled us out?!” Thus, the poor man’s right would be lost.
The correct view, then, is that once a person has undertaken testimony and is summoned, he is individually obliged to deliver it, even if there were no evidence for this other than Allah’s saying:
“Do not conceal testimony, for whoever conceals it—his heart is indeed sinful.” [al-Baqarah 2:283]