John Calvin Commentary Acts 13:28

"And though they found no cause of death [in him], yet asked they of Pilate that he should be slain." — Acts 13:28 (ASV)

Although they found no cause of death. It was very relevant that they should know that Christ was put to death though innocent, for we could not have been justified by His death if He had suffered death for His own wrongdoings. Therefore, it was necessary that He should be guiltless, so that His death might be a satisfaction for the sins of the world.

And, undoubtedly, I think that Paul clearly stated that Pilate condemned Christ not in his official capacity as a judge, but rather consented to His death after being overcome by the wicked demands of the people. I believe he also plainly stated that the Jews were driven by malice, and not compelled by reason, to desire Christ’s death. For it was important for him to terrify the hearers, so that they might not associate themselves with such a wicked act. But Luke now briefly records, as is his usual custom, those things which Paul then declared more fully.