Translation:

43. But why do they come to thee for decision when they have (their own) laws before them? Therein is the (plain) command of Allah; yet even after that they would turn away. For they are not (really) people of faith.

Notes (Tafseer)

749. This is a searching question as to the motive of the Jews in bringing their cases for decision to the Prophet. They came either (1) to ridicule whatever he said, or (2) to deceive him as to facts and snatch a favourable decision which was against equity. If their own Law did not suit their selfish interests, they sometimes twisted it. But Muhammad was always inflexible in his justice.