John Mark
Mark 6:17BSB·traditional attribution

For Herod himself had ordered that John be arrested and bound and imprisoned, on account of his brother Philip’s wife Herodias, whom Herod had married.

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. The wild notions that the people had concerning our Lord Jesus, Mar 6:15. His own countrymen could believe nothing great concerning him, because they knew his poor kindred; but others that were not under the power of that prejudice against him, were yet willing to believe any thing rather than the truth - that he was the Son of God, and the...

Commenting on Mark 6:14-29

John Gill Reformed Baptist @doctorgill

For Herod himself had sent forth,.... Some of his guard, a detachment of soldiers, and laid hold upon John; who seized upon him, and took him up: and bound him in prison; in the castle of Machaerus: for Herodias' sake, his brother Philip's wife, for he had married her; whilst his brother was living, and who had had children by her; See Gill on Mat 14:3.