אֽוֹ־עָשִׂ֤יתִי בנפשו [בְנַפְשִׁי֙] שֶׁ֔קֶר וְכָל־דָּבָ֖ר לֹא־יִכָּחֵ֣ד מִן־הַמֶּ֑לֶךְ וְאַתָּ֖ה תִּתְיַצֵּ֥ב מִנֶּֽגֶד׃
Otherwise if I had dealt falsely against mine own life—and there is no matter hid from the king—then thou thyself wouldest have stood aloof.’
Read midrashic interpretation of II Samuel 18:13: and classical rabbinic exegesis.