Verse 20: And he said unto Jether his firstborn, Up, and slay them. But the youth drew not his sword: for he feared, because he was yet a youth.
[And he said to Jether, Arise, and slay, etc.] Question: Why did he will them to be killed by his son? Responses: 1. So that he might avenge the death of his uncles. 2. So that they might die with greater suffering and shame: For only by many and repeated blows are such killed by such. 3. So that he might make him a partaker of the victory and glory (Serarius, Menochius). 4. So that he might excite his spirit against the enemies of God’s people from his tender years; as it is written of Hannibal, that he devoted himself to opposing the Romans from his youth: and so that from his youth he might learn to obey the Divine Law, by which the shedding of the blood of near relations was commanded to be avenged. Moreover, formerly it was not dishonorable to slay the guilty: For the ancient Hebrews do not appear to have had executioners. Saul commanded the nobles to kill the priests; Samuel killed Agag with his own hand; and Benaniah, Joab (Martyr).
Up, and slay them; partly, that he might animate him to the use of arms for his God and country against their enemies, and to the exercise of justice; partly, that the death of those mischievous persons might be more shameful and painful; and partly, that he might have some share in the honour of the victory.
[For he was afraid] For these Kings appear to have been of great stature, fierce countenance, and not even dismayed by the fear of death (Serarius).
Verse 21: Then Zebah and Zalmunna said, Rise thou, and fall upon us: for as the man is, so is his strength. And Gideon arose, and (Ps. 83:11) slew Zebah and Zalmunna, and took away the ornaments (or, ornaments like the moon) that were on their camels’ necks.
[According to the age of man so is his strength, כָאִ֖ישׁ גְּבוּרָת֑וֹ] As a man is, his strength is (Vatablus, similarly Montanus, Junius and Tremellius, Syriac, Piscator). Strength corresponds to age and stature: That one is small; he does not have the strength that he might be able to kill us (Vatablus). Whom the lad kills, he dies a slow and ignominious death (Drusius, similarly Lyra).
As the man is, so is his strength: thou excellest him, as in age and stature, so in strength; and it is more honourable, as well as easy, to die by the hands of a valiant man.
[He took the ornaments and amulets, אֶת־הַשַּׂהֲרֹנִים] The crescent shaped ornaments (Septuagint, Syriac, Arabic, Montanus, Junius and Tremellius, Piscator, Pagnine, Grotius, Drusius), that is, the ornaments have the figure of the Moon (Drusius, Vatablus, the Rabbis in Munster). An emblem of the Ishmaelites; of whom the Saracens being a part, they transmitted their customs to the Turks (Grotius). Collars (Jonathan). Malvenda translates it roundnesses, ornaments with bosses (Junius). סוֹהַר is roundness (Malvenda); and סִיהַרָא/ Sihara in the Chaldean Paraphrase is the Moon (Bonfrerius, Malvenda). This word is found here, and below in verse 26, and in Isaiah 3:18 (Bonfrerius).
 Hebrew: וַ֙יֹּאמֶר֙ לְיֶ֣תֶר בְּכוֹר֔וֹ ק֖וּם הֲרֹ֣ג אוֹתָ֑ם וְלֹא־שָׁלַ֙ף הַנַּ֤עַר חַרְבּוֹ֙ כִּ֣י יָרֵ֔א כִּ֥י עוֹדֶ֖נּוּ נָֽעַר׃
 1 Samuel 22:17.
 1 Samuel 15:32, 33.
 1 Kings 2:34.
 Hebrew: וַיֹּ֜אמֶר זֶ֣בַח וְצַלְמֻנָּ֗ע ק֤וּם אַתָּה֙ וּפְגַע־בָּ֔נוּ כִּ֥י כָאִ֖ישׁ גְּבוּרָת֑וֹ וַיָּ֣קָם גִּדְע֗וֹן וַֽיַּהֲרֹג֙ אֶת־זֶ֣בַח וְאֶת־צַלְמֻנָּ֔ע וַיִּקַּח֙ אֶת־הַשַּׂ֣הֲרֹנִ֔ים אֲשֶׁ֖ר בְּצַוְּארֵ֥י גְמַלֵּיהֶֽם׃
 Hebrew: אֶת־הַשַּׂהֲרֹנִים.
 Judges 8:26: “And the weight of the golden earrings that he requested was a thousand and seven hundred shekels of gold; beside ornaments (הַשַּׂהֲרֹנִים), and collars, and purple raiment that was on the kings of Midian, and beside the chains that were about their camels’ necks.”
 Isaiah 3:18: “In that day the Lord will take away the bravery of their tinkling ornaments about their feet, and their cauls, and their round tires like the moon (וְהַשַּׂהֲרֹנִים)…”