one way of ensuring silence

Several voices echoed the fierce appeal, but amongst the wild cries for revenge, the ear of Lycidas, and the ear of the leader also, caught the maiden's faint exclamation, "Oh, Judas, have mercy! spare him!"
Still the extended hand of the chief alone kept back the fierce band who would have cut down their defenceless victim. But there was painful doubt on the brow of the leader; not that he was influenced by the demand for blood from Abishai and his fierce companions, but that he was aware of the extreme risk of setting the captive free. Lycidas felt that his fate hung on the lips of that calm princely man, and was almost satisfied that so it should be; a thought rose in the mind of the Greek, "If I must die, let it be by his hand."
"Stranger," began the son of Mattathias, and at the sound of his voice the tumult was hushed, and all stood silent to listen; "I doubt not your word, I thirst not for your blood--were my own life only at stake, not a hair of your head should be harmed. But on your silence as to what you have seen this night depends the safety of all here assembled, even of these daughters of Zion, for the tyrant spares not our women. We have no power to detain in captivity--we have but one way of ensuring silence; would you yourself--with the grave of those martyrs before you--be able to reproach us with cruelty should we decide on taking that way?"
Lycidas met without blenching the calm sad eyes of the speaker, but he could not answer the question. He knew that under like circumstances neither Syrian nor Greek would feel hesitation before, or remorse after, what would be deemed a stern deed of necessity. The eloquent lips of the poet had no power to plead now for life.
"Why waste words!" exclaimed fierce Abishai; "why do you hesitate, Judas? One would scarce deem you to be the descendant of that Phineas who won deathless fame by smiting Zimri and Cosbi through with a dart. 'Thine eye shall not pity, nor thine hand spare.' Guilt lies on your head if you let Agag go. Was not the Canaanite to be rooted out of the land? Who dare bid us draw back when the Lord hath delivered the prey to our swords?"
"I dare--I do," cried Hadassah, advancing with dignity to the edge of the grove which separated her and her grand-daughter Zarah from the Hebrew men and their captive. "Shame on you, Abishai, man of blood. Yea, though you be the husband of my dead daughter, I repeat, shame on you to bring the name of the Lord to sanction your own thirst for vengeance! Hear me, son of Mattathias; ye men of Judah, hear me. The Merciful bids me speak, and I cannot refrain from speaking the words which He puts into my mouth.