Mark 6:19

“Therefore Herodias had a quarrel against him, etc..] Was angry with him, conceived wrath, and laid up hatred against him, and was an adversary to him; which is the sense of the Oriental versions. She bore him an inward grudge, and lay in wait to take the first opportunity of dispatching him: and would have killed him, but she could not; being hindered by Herod, who as yet would not suffer it; partly through fear of the people, and partly through the respect he had for John.”

“See this account of the death of John the Baptist fully explained in the notes at Matthew 14:1-12. Mark 6:20 For Herod feared John - That is, he stood in awe of him on account of his sanctity, and his boldness and fearlessness in reproving sin. Knowing that he was a just man and an Holy - A holy, pious, upright, honest man - a man who would not be afraid of him, or afraid to speak his real sentiments. And observed him - Margin, “kept him, or saved him.” This does not mean that he “observed” or obeyed his teachings, but that he kept him in safe custody in order to preserve him from the machinations of Herodias. He was willing to show his respect for John, and to secure him from danger, and…”

“6:19-28 Herodias’s role in the murder of John the Baptist recalls the story of Jezebel (1 Kgs 19:1-2). Herod succumbed to pressure (Mark 6:26-28), which foreshadows the later story of Pontius Pilate, who put Jesus to death against his better judgment (cp. 6:20, 25-28 with 15:6-15).”

“Herodias: Gen 39:17-20; Kg1 21:20 a quarrel: or, an inward grudge, Ecc 7:9; Eph 4:26, Eph 4:27 Mark 6:20”