Albert Barnes Commentary John 7:19

"Did not Moses give you the law, and [yet] none of you doeth the law? Why seek ye to kill me?" — John 7:19 (ASV)

Did not Moses give you the law? This they admitted, and on this they prided themselves. They considered every violation of that law as deserving of death. They had accused Jesus of violating it because he had healed a man on the Sabbath, and for that, they had sought his life (John 5:10–16). He here reminds them of that charge, and shows them that, though they pretended great reverence for that law, yet they were really its violators in having sought his life.

None of you, etc. None of you Jews. They had sought to kill him. This was a pointed and severe charge, and shows the great faithfulness with which he was accustomed to proclaim the truth.

Why go ye about to kill me? Why do you seek to kill me? See John 5:16.