שָׁמַ֤עְתָּֽ חֲזֵה֙ כֻּלָּ֔הּ וְאַתֶּ֖ם הֲל֣וֹא תַגִּ֑ידוּ הִשְׁמַעְתִּ֤יךָ חֲדָשׁוֹת֙ מֵעַ֔תָּה וּנְצֻר֖וֹת וְלֹ֥א יְדַעְתָּֽם׃
Thou hast heard, see, all this; And ye, will ye not declare it? I have announced unto thee new things from this time, Even hidden things, which thou hast not known.
Read Jewish philosophy on Isaiah 48:6: Rambam's Guide for the Perplexed, Saadia Gaon, and classical Jewish philosophical sources, free online.