Albert Barnes Commentary Acts 13:27

"For they that dwell in Jerusalem, and their rulers, because they knew him not, nor the voices of the prophets which are read every sabbath, fulfilled [them] by condemning [him]." — Acts 13:27 (ASV)

Because they knew him not. The statement in this verse is designed, not to reproach the Jews at Jerusalem, but to introduce the fact that Jesus had died, and had risen again. With great wisdom and tenderness, he speaks of his murderers in such a manner as not to exasperate, but as far as possible to mitigate their crime. There was sufficient guilt in the murder of the Son of God to overwhelm the nation with alarm, even after all that could be said to mitigate the deed. See Acts 2:23, 36, 37.

When Paul says, They knew him not, he means that they did not know him to be the Messiah (see 1 Corinthians 2:8). They were ignorant of the true meaning of the prophecies of the Old Testament; they regarded him as an impostor. See Barnes Acts 3:17.

Nor yet the voices of the Prophets. That is, they did not understand the meaning of the predictions in the Old Testament respecting the Messiah. They expected a prince and a conqueror, but did not expect a Messiah who was poor and despised, a man of sorrows, and who was to die on a cross.

Which are read every sabbath day. In the synagogues. Though the Scriptures were read so constantly, yet they were ignorant of their true meaning. They were blinded by pride, prejudice, and preconceived opinions. Men may often in this way read the Bible a good part of their lives, and, for want of attention or of a humble mind, never understand it.

They have fulfilled them, etc. By putting him to death, they have accomplished what was foretold.

Voices of the Prophets ("Words"). They have fulfilled them (Luke 24:20, 44).