For he knew that for envy - This was envy at his popularity.
He drew away the people from them. This Pilate understood, probably, from his knowledge of the pride and ambition of the rulers, and from the fact that no danger could arise from a person that appeared like Jesus. If Pilate knew this, he was bound to release him himself. As a governor and judge, he was under obligation to protect the innocent, and should, in spite of all the opposition of the Jews, at once have set him at liberty. But the Scriptures could not then have been fulfilled. It was necessary, in order that an atonement should be made. that Jesus should be condemned to die. At the same time. it shows the wisdom of the overruling providence of God, that he was condemned by a man who was satisfied of his innocence, and who proclaimed before his accusers his "full belief" that there was no fault in him.

For envy - Δια φθονον, through malice. Then it was his business, as an upright judge, to have dispersed this mob, and immediately released Jesus.
Seeing malice is capable of putting even Christ himself to death, how careful should we be not to let the least spark of it harbor in our breast. Let it be remembered that malice as often originates from envy as it does from anger.

For he knew that for envy they had delivered him. He saw in their countenances, and by their charges against him, and by the whole of their conduct, that it was not out of any regard to Caesar, or to the peace and tranquillity of the civil government, or to strict justice; but from envy, at his popularity, at his fame and credit, the honour, glory, and applause he had among the people, on account of his doctrine, and miracles, that they had delivered him up into his hands; and therefore Pilate might the rather hope to succeed in this scheme of his to release him, by proposing him with so notorious a person to the populace, when the one, as he might reasonably judge, was abhorred by them, and the other had got great credit and esteem among a large number of them. The Persic version here adds the people's answer; "they answered, release Barabbas, but deliver Jesus to us".

He knew that for envy they had delivered him - As well as from malice and revenge; they envied him, because the people magnified him.