What is the ruling on a group of people testifying that a benefactor built a mosque previously, when this contradicts the truth, and what are the implications of that regarding prayer in the mosque?

It is not permissible for the person who donated to rebuild the mosque to ask people to bear false witness that he built it previously, nor is it permissible for them to agree to that, due to the Almighty's saying: {And those who do not bear false witness}, and the Prophet's (peace and blessings be upon him) saying: "Beware of false speech, beware of false witness." If they bore false witness for him, they must repent and seek forgiveness. Prayer in the mosque is valid even if they bore witness for him and he undertook its construction.