What is the meaning of "u'Maltem es Orlas Levavchem!"?
Rashi: It means 'Remove that which stops up the heart and blocks it!' - from understanding the words of Hashem. 1
Seforno: It means 'Remove the foreskin (the blockage) of the intellect - erroneous thoughts that create warped Hashkafos (outlook - opinions).
Targum Onkelos and Targum Yonasan: It means 'Remove the foolishness of your hearts!'
What are the implications of "v'Orpeechem Lo Sakshu Od!"?
Ramban: It implies that they should stop being stubborn like their fathers, who learned from the Egyptians and were incapable of changing their ways, causing them to commit the sin of the Eigel ha'Zahav, following which Hashem called them "Am Keshei Oref". 1
Seforno: 'And cease being stubborn' - thereby enabling you to turn towards acknowledging your Creator and seeing how bitter it is to forsake Him.
See Ramban who elaborates.