The Quran

وَإِذ قالَ موسىٰ لِقَومِهِ يا قَومِ لِمَ تُؤذونَني وَقَد تَعلَمونَ أَنّي رَسولُ اللَّهِ إِلَيكُم ۖ فَلَمّا زاغوا أَزاغَ اللَّهُ قُلوبَهُم ۚ وَاللَّهُ لا يَهدِي القَومَ الفاسِقينَ

Muhammad Asad

Now when Moses spoke to his people, [it was this same truth that he had in mind:] "O my people! Why do you cause me grief,¹ the while you know that I am an apostle of God sent unto you?" And so, when they swerved from the right way, God let their hearts swerve from the truth:² for God does not bestow His guidance upon iniquitous folk.

Sc., "by admitting that I speak in the name of God, and acting contrary to this you assertion": an allusion to the many instances of the contrariness and rebelliousness of the children of Israel evident from their own scriptures.
Thus, persistence in wrong actions is bound to react on man's beliefs as well. As regards God's "letting their hearts swerve from the truth", see surah 14, note 4. Cf. also the oft-recurring reference to God's "sealing" a sinner's heart explained in note 7 on 2:7.