חָקְרֵ֣נִי אֵ֭ל וְדַ֣ע לְבָבִ֑י בְּ֝חָנֵ֗נִי וְדַ֣ע שַׂרְעַפָּֽי׃
Search me, O God, and know my heart, Try me, and know my thoughts;
Read Midrashic interpretations of Psalms 139:23: rabbinic exegesis from Bereshit Rabbah, Shemot Rabbah and classical Midrash sources, free.