Word by Word Analysis

وَكَيْفَ يُحَكِّمُونَكَ وَعِندَهُمُ ٱلتَّوْرَىٰةُ فِيهَا حُكْمُ ٱللَّهِ ثُمَّ يَتَوَلَّوْنَ مِنۢ بَعْدِ ذَٰلِكَ ۚ وَمَآ أُو۟لَـٰٓئِكَ بِٱلْمُؤْمِنِينَ 43

But how is it that they come to you for judgement while they have the Torah, in which is the judgement of Allāh? Then they turn away, [even] after that; but those are not [in fact] believers.