This means that if people say that the king was wrong for helping the woman's family that the king should not be guilty. The full meaning of this statement can be made explicit. Alternate translation: "if anyone blames you for helping our family, may my family be considered guilty instead" (See: [[rc://en/ta/man/jit/figs-explicit]])
Here the word "throne" refers to anyone who later becomes king in David's place. Alternate translation: "The king and his descendants" or "The king and his family" (See: [[rc://en/ta/man/jit/figs-metonymy]])
"are innocent." This implies that in the future if anyone accuses the king of wrongdoing, he will be innocent in the matter. Alternate translation: "will be innocent regarding the matter" (See: [[rc://en/ta/man/jit/figs-explicit]])