What is the ruling on Sa’d ibn Abi Waqqas, may Allah be pleased with him, supplicating against Usamah ibn Qatadah for discord, and what was the reason for it, knowing that it is not permissible for a Muslim to transgress in supplication?

It is permissible for a Muslim to supplicate against one who has wronged him, without exceeding the bounds. Sa’d ibn Abi Waqqas supplicated against the one who wronged him, observing justice and fairness. In response to the man’s false accusations, he supplicated against him with what corresponded to them: poverty, a long life, and exposure to tribulations. He made his supplication conditional on the accuser being a liar.