John Chrysostom

"Blood and fire, and vapor of smoke." Observe how he describes the capture. "The sun shall be turned into darkness, and the moon into blood." This results from the internal affection of the sufferers. It is said, indeed, that many such phenomena actually did occur in the sky, as Josephus attests. At the same time the Apostle strikes fear into them, by reminding them of the darkness which had lately occurred, and leading them to expect things to come.

Homily on Acts 5 ↗

Theophylact of Ohrid

With these words the prophet clearly foretells in advance both the future judgment, and the destruction of Jerusalem, and the captivity of the Jews, and the events that were to take place at the cross of Christ, and finally, what happened to the Jews as a result of the Roman war, when much blood was shed by the Romans in Judea, when smoke billowed from the burning of cities and villages. …

Commentary on Acts ↗

Oecumenius

Now, "The sun shall be turned into darkness," and the preceding, "blood and fire and vapor of smoke," these refer to the coming judgment. More appropriately and specifically they speak of Jerusalem and its then captivity, as is shown by the nature of those suffering. Likewise, according to Josephus, many such things foreshadowed the destruction of Jerusalem. That the moon is said to be turned into blood signifies the excess of slaughter, being nearer to the earth and able to suffer this from the exhalation of blood. …

Commentary on Acts ↗

Bede

Blood and fire and vapor of smoke. The blood of the Lord's side, the fire of the Holy Spirit, the vapor of compunction and weeping. For as from fire comes smoke, so from the ardor of the Holy Spirit proceeds compunction. For it remains to believe that blood flowed from a dead body in a living stream, which is against the nature of our bodies, was done as an indication of a sign. For what other purpose, unless for our salvation and life, which indeed springs from His death? …

Commentary on Acts ↗