Now therefore stand still, that I may plead with you before Yahweh concerning all the righteous acts of Yahweh, which he did to you and to your fathers.
In other words, he is declaring his innocency before the people. "Look, I didn't take from you at all. I didn't take from you your oxen, your donkeys. I didn't accept bribes. I've not oppressed you. If anyone feels that I've oppressed you, anyone feels I've defrauded, step forward, and I will pay." Really Samuel did have a very beautiful and remarkable career as the judge of Israel. Extremely outstanding person.