"It guides to the right path," meaning: it clarifies the way of guidance. "So we have believed in it," and they were before that, as it is mentioned, upon Judaism.
﴿يهدي إِلَى الرشد﴾ أَيْ: يُبَيِّنُ سَبِيلَ الْهُدَى ﴿فَآمَنَّا بِهِ﴾ وَكَانُوا قَبْلَ ذَلِكَ فِيمَا ذُكِرَ على الْيَهُودِيَّة.
