“Matthew 27:24-25. When Pilate saw that he could prevail nothing — That he could not convince them what an unjust, unreasonable thing it was for him to condemn a man whom he believed to be innocent, and whom they could not prove to be guilty; and that instead of doing any good by his opposition to their will, a tumult was made — Through their furious outcries; he took water, and washed his hands before the multitude — Pilate did this, says Origen, according to the custom of the Jews, being willing to assert Christ’s innocency to them, not in words only, but by deed. Thus, in the instance of a murder, committed by an unknown hand, the elders of the city nearest to the place where the dead body was found, were to wash their hands over a heifer slain by way of sacrifice to expiate the crime, and to say, Our hands have not shed this blood, Deuteronomy 21:6. Alluding to which ceremony, the psalmist, having renounced all confederacy with wicked and mischievous men, says, I will wash my hands in innocency. But as washing the hands in token of innocence was a rite frequently used. also by the Gentiles, it is much more probable that Pilate, who was a Gentile, did this in conformity to them. He thought, possibly, by this avowal of his resolution to have no hand in the death of Christ, to have terrified the populace; for one of his understanding and education could not but be sensible that all the water in the universe was not able to wash away the guilt of an unrighteous sentence. Saying, I am innocent of the blood of this just person: see ye to it — Nevertheless, solemn as his declaration was, it had no effect; for the people continued inflexible, crying out with one consent, His blood be on us and on our children — That is, We are willing to take the guilt of his death upon ourselves. The governor, therefore, finding by the sound of the cry that it was general, and that the people were fixed in their choice of Barabbas, passed the sentence they desired. He released unto them him that for sedition and murder was cast into prison, whom they had desired, but he delivered Jesus to their will, Luke 23:25. In this conduct, notwithstanding his efforts to save Jesus, he was utterly inexcusable, and the more so the more he was convinced of Christ’s innocence. He had an armed force under his command sufficient to have scattered this infamous mob, and to have enforced the execution of a righteous sentence. But if not, he ought himself rather to have suffered death than to have knowingly condemned the innocent. Accordingly, as the ancient Christians believed, great calamities afterward befell him and his family, as a token of the displeasure of God for his perversion of justice in this instance. According to Josephus, he was deposed from his government by Vitellius, and sent to Tiberius at Rome, who died before he arrived there. And we learn from Eusebius, that quickly after, having been banished to Vienne in Gaul, he laid violent hands upon himself, falling on his own sword. Agrippa, who was an eye-witness to many of his enormities, speaks of him, in his oration to Caius Cesar, as one who had been a man of the most infamous character.

As to the imprecation of the Jewish priests and people, His blood be on us and on our children, it is well known, that as it was dreadfully answered in the ruin so quickly brought on the Jewish nation, and the calamities which have since pursued that wretched people in almost all ages and countries; so it was particularly illustrated in the severity with which Titus, merciful as he naturally was, treated the Jews whom he took during the siege of Jerusalem; of whom Josephus himself writes, [Bell. Jud., 50. 5:11, (al. Matthew 6:12,) § 1,] that μαστιγουμενοι ανεσταυρουντο, having been scourged, and tortured in a very terrible manner, they were crucified in the view and near the walls of the city; perhaps, among other places, on mount Calvary; and it is very probable, this might be the fate of some of those very persons who now joined in this cry, as it undoubtedly was of many of their children. For Josephus, who was an eye-witness, expressly declares, “that the number of those thus crucified was so great that there was not room for the crosses to stand by each other; and that at last they had not wood enough to make crosses off.” A passage which, especially when compared with the verse before us, must impress and astonish the reader beyond any other in the whole story. If this were not the very finger of God, pointing out their crime in crucifying his Son, it is hard to say what could deserve to be called so. Elsner has abundantly shown, that among the Greeks, the persons on whose testimony others were put to death used, by a very solemn execration, to devote themselves to the divine vengeance, if the person so condemned were not really guilty.”
-Benson Commentary