אֲדֹנָ֤י יְהוִה֙ פָּתַֽח־לִ֣י אֹ֔זֶן וְאָנֹכִ֖י לֹ֣א מָרִ֑יתִי אָח֖וֹר לֹ֥א נְסוּגֹֽתִי׃
The Lord GOD hath opened mine ear, And I was not rebellious, Neither turned away backward.
Read Jewish philosophy on Isaiah 50:5: Rambam's Guide for the Perplexed, Saadia Gaon, and classical Jewish philosophical sources, free online.