Verse 5: And he went unto his father’s house (Judg. 6:24) at Ophrah, and (2 Kings 11:1, 2) slew his brethren the sons of Jerubbaal, being threescore and ten persons, upon one stone: notwithstanding yet Jotham the youngest son of Jerubbaal was left; for he hid himself.
[He killed his brethren] As the Turks do now (Grotius). For ambition is cruel, pitiless, suspicious (Bonfrerius, Serarius).
The sons of Jerubbaal; the only persons who were likely to hinder him in establishing his tyranny.
[Seventy] By rounding the number: For Jotham escaped (Drusius, Serarius, Lapide). Synecdoche, as in verse 56. See on Genesis 35:26 (Malvenda). Thus Judges 9:18. Likewise in Genesis 42:13, we are twelve brethren, although they believe one dead. Thus in John 20:24, Thomas, one of the twelve, although there were only eleven. Thus, He showed Himself to the twelve disciples, although Judas had departed. Or, perhaps Jotham was a son of one of the slain sons. Just as Canaan is called Noah’s youngest son, according to some (Drusius). Moreover, יוֹתָם/Jotham appears to have received his name as a presage of his calamity, which signifies Ward, or Orphan; for he was bereaved of sixty-nine brethren (Malvenda).
Threescore and ten persons; wanting one, who is here expressed; and these synecdochical expressions are frequent in Scripture: see Genesis 35:26; 42:13; Numbers 14:32, 33; John 20:24; 1 Corinthians 15:5.
[Upon one stone] Question: Why thus? Responses: 1. Because he desired to appear to play the part, not of an enemy, but of a Judge; as if they were found guilty of some crime, either against Abimelech, or against their country (Tostatus). It is thought to have been some eminent stone, chosen to be a place of punishment (Martyr). 2. So that the people might understand that that slaughter, as a sacrifice to Baal the avenger, was done in the name of religion. For we read in 1 Samuel 6 that stones of this sort were used in the place of altars. And Jerubbaal himself had sacrificed upon a stone with his fire kindled from wood cut down from Baal’s grove, whence he had incurred the great displeasure of those living nearby, the embers of which, although they were lying in the breasts of some under the ashes of dissimulation, yet burned, as after his death that first and swiftest care of renewing the worship of Baal was able to argue. And so, under the pretext of expiating that offense, for that bull, Judges 6, and cut down grove, the seventy sons of Jerubbaal are appointed (Montanus’ Commentary). Hence also the Shechemites, on behalf of their Baal restored to them, appear to have reckoned to him for the heads of his slaughtered brethren just so many pieces of silver by weight (Lapide). 3. This stone was found suitable, upon which these might lay their heads to be cut off (Bonfrerius).
Upon one stone; whereby he would signify that this was either, 1. An act of justice, in cutting them all off in an orderly manner, for some supposed crime, probably as designing sedition and rebellion; or, 2. An act of religion, in avenging the dishonour and injury done to Baal by Gideon, Judges 6:27, 28, upon his children, whom he offered up as so many sacrifices to Baal upon this stone, which served for an altar; and for this reason it seems the money was taken out of Baal’s house, because it was to be laid out in his service.
[He was hidden] Either, he escaped by flight; or, he was hidden by the others (Bonfrerius).
 Hebrew: וַיָּבֹ֤א בֵית־אָבִיו֙ עָפְרָ֔תָה וַֽיַּהֲרֹ֞ג אֶת־אֶחָ֧יו בְּנֵֽי־יְרֻבַּ֛עַל שִׁבְעִ֥ים אִ֖ישׁ עַל־אֶ֣בֶן אֶחָ֑ת וַיִּוָּתֵ֞ר יוֹתָ֧ם בֶּן־יְרֻבַּ֛עַל הַקָּטֹ֖ן כִּ֥י נֶחְבָּֽא׃
 See Genesis 9:24.
 יָתוֹם signifies orphan.
 See Judges 6:26, 28.