Now about that time Herod the king stretched forth his hands to vex certain of the church. Herod the king - This was Herod Agrippa, the son of Aristobulus, and grandson of Herod the Great; he was nephew to Herod Antipas, who beheaded John they Baptist, and brother to Herodias. He was made king by the Emperor Caligula, and was put in possession of all the territories formerly held by his uncle Philip and by Lysanias; viz. Iturea, Trachonitis, Abilene, with Gaulonitis, Batanaea, and Penias. To these the Emperor Claudius afterwards added Judea and Samaria; which were nearly all the dominions possessed by his grandfather, Herod the Great. See Luke 3:1; see also an account of the Herod family, in the note on Matthew 2:1 (note).
To vex certain of the Church - That is, to destroy its chief ornaments and supports.