Verse 19: There was not a city that made peace with the children of Israel, save (Josh. 9:3, 7) the Hivites the inhabitants of Gibeon: all other they took in battle.
[There was not a city, etc.] He gives the reason for the long-lasting war; namely, by force of arms was the matter to be conducted against a most obstinate enemy, and ἄσπονδον/implacable, and full of desperation (Masius).
There was not a city, etc.: To wit, all that were taken by Joshua, were taken by the sword, and therefore it is no wonder that the war was long, when the enemy was so obstinate.
[All he took] Namely, either, those that were mentioned above, or, unto which Joshua approached with arms (Masius out of Augustine).
Verse 20: For (Deut. 2:30; Judg. 14:4; 1 Sam. 2:25; 1 Kings 12:15; Rom. 9:18) it was of the LORD to harden their hearts, that they should come against Israel in battle, that he might destroy them utterly, and that they might have no favour, but that he might destroy them, (Deut. 20:16, 17) as the LORD commanded Moses.
[It was the decree of the Lord that their hearts might be hardened,מֵאֵ֣ת יְהוָ֣ה׀ הָיְתָ֡ה לְחַזֵּ֣ק אֶת־לִבָּם֩] It was from the Lord to strengthen (or, to harden [Dutch]) their heart (Montanus). [Some refer this to God:] That He, namely, God, might harden (Pagnine), or, make obdurate (Drusius); who hardened, or strengthened (Munster, Tigurinus). He rendered their heart hard (Arabic). [Others refer this to the Canaanites:] That they might make obdurate their heart (Masius); that they were making obdurate their heart, etc. (Junius and Tremellius); so that, with obstinate hearts, they might rush to war, etc. (Castalio); or, so that their hearts might be made obdurate (Drusius, similarly the Syriac). Thus לִקְרֺא in Genesis 4:26 signifies to be called (Drusius). Of itself it is an ambiguous expression, whether God hardened the heart of the Canaanites, or they hardened their own. And certainly either is rightly able to be said, as it is evident from Exodus 9:12, 34; 14:17; Deuteronomy 2:30 (Masius). The doubling of the preposition, from unto God, or, from with God, it was, is not without emphasis, to indicate the great and most secret methods of the Divine Providence to harden and overthrow them (Malvenda). God did not send among them terror as He was able; indeed, He also withdrew much of their prudence (Grotius). The language of heart is put for the mind (Masius).
[And they might fight against Israel, לִקְרַ֙את הַמִּלְחָמָ֤ה אֶת־יִשְׂרָאֵל֙] Unto an encounter of war with Israel (Pagnine, Montanus). It is a Hebraism; with war imminent with Israel (Vatablus). To set in order battle with Israel (Jonathan); so that they might rush to war, etc. (Arabic, similarly Junius and Tremellius, Syriac, Septuagint, Munster, Tigurinus).
[And they might not find any mercy, לְבִלְתִּ֥י הֱיוֹת־לָהֶ֖ם תְּחִנָּ֑ה] So that by no means, or not, there might be, or be found, for them grace, or mercy, or compassion (Malvenda, Junius and Tremellius, similarly the Septuagint, Jonathan, Syriac, Arabic, Vatablus). So that they might not pity them (Vatablus). So that they might be completely uprooted by the Israelites without any mercy, by which we are wont to be moved, not towards those opposing, but towards supplicants (Masius).
It was of the Lord, etc.: It was the design of God’s providence not to soften their hearts to a compliance with the Israelites, but to give them up to their own animosity, pride, confidence, and stubbornness; that so both their abominable and incorrigible wickedness might be severely punished and that the Israelites might not be mixed with them, but be entire among themselves in the possession of the land. Compare Deuteronomy 2:30, and for the phrase, Exodus 7:13; 9:12; 14:17.
 Hebrew: לֹא־הָיְתָ֣ה עִ֗יר אֲשֶׁ֤ר הִשְׁלִ֙ימָה֙ אֶל־בְּנֵ֣י יִשְׂרָאֵ֔ל בִּלְתִּ֥י הַחִוִּ֖י יֹשְׁבֵ֣י גִבְע֑וֹן אֶת־הַכֹּ֖ל לָקְח֥וּ בַמִּלְחָמָֽה׃
 Hebrew: כִּ֣י מֵאֵ֣ת יְהוָ֣ה׀ הָיְתָ֡ה לְחַזֵּ֣ק אֶת־לִבָּם֩ לִקְרַ֙את הַמִּלְחָמָ֤ה אֶת־יִשְׂרָאֵל֙ לְמַ֣עַן הַֽחֲרִימָ֔ם לְבִלְתִּ֥י הֱיוֹת־לָהֶ֖ם תְּחִנָּ֑ה כִּ֚י לְמַ֣עַן הַשְׁמִידָ֔ם כַּאֲשֶׁ֛ר צִוָּ֥ה יְהוָ֖ה אֶת־מֹשֶֽׁה׃
 Genesis 4:26: “And to Seth, to him also there was born a son; and he called his name Enos: then began men to call upon the name of the Lord (לִקְרֹ֖א בְּשֵׁ֥ם יְהוָֽה׃, to be called by the name of the Lord).” The infinitive is formally active, but may be taken in a passive sense.
 קָרָא can signify to meet or encounter, or to call.