Verse 20: And David rose up early in the morning, and left the sheep with a keeper, and took, and went, as Jesse had commanded him; and he came to the trench (or, place of the carriage, 1 Sam. 26:5), as the host was going forth to the fight (or, battle array, or, place of fight), and shouted for the battle.
[He arose in the morning] He did not delay, because he loved his brethren, and honored his parents (Sanchez).
[He departed laden, וַיִּשָּׂא] And he carried, or brought (Montanus, Septuagint, Jonathan); he carried those things (Syriac, similarly Tigurinus, Castalio); conveying the aforementioned things (Munster, similarly the Arabic); he loaded himself (Pagnine).
[He came to the place of Magala, הַמַּעְגָּלָה] A great many take this as an appellative (Malvenda). They translate it, to or within, the circumvallation (Pagnine, Montanus, Vatablus, Castalio); to the camp (Jonathan, Syriac); to the army (Syriac, Arabic, Vatablus), or, to the place of the army (Vatablus); into the circumvallation of the camp (Tigurinus, Strigelius), to the place in which the Israelites had pitched their tents. Now, it is thus called a circumvallation, because it is in a rounded form (Vatablus); as it is customary (Malvenda). To the circuit of the carts, that is, to the place of the baggage, with which the camp had been surrounded, as in 1 Samuel 26:5. It is a Synecdoche; Carts for ever sort of impediment (Piscator out of Junius).
To the trench, that is, to the camp or army which was there intrenched.
[And to the army, which, having gone forth to fight, shouted (thus the Septuagint rightly translates the Hebrew words [Dieu]), וְהַחַ֗יִל הַיֹּצֵא֙ אֶל־הַמַּ֣עֲרָכָ֔ה] A great many, following the Chaldean, read it as if it were written הַחַיִל יֹצֵא, the army was going forth. But it is a different construction, הַחַיִל הַיֹּצֵא (Dieu); [as mentioned] and the army had gone out (or was led out [Strigelius]) to the company (Montanus), to or unto the battle line (Munster, Tigurinus, Strigelius), so that it might be arranged into a battle line (Vatablus).
[It shouted in the contest, וְהֵרֵ֖עוּ בַּמִּלְחָמָֽה׃] And they shouted (sounded [Jonathan]) in the battle (Pagnine, Montanus, Jonathan), in the fight (Munster). They had sounded (had cried out [Arabic], were sounding the trumpet [Tigurinus]) to the battle, or fight (Syriac, Arabic, Tigurinus, Junius and Tremellius, Piscator). To this end, that they might provoke the Philistines to battle. The preposition ב here denotes the final cause (Piscator). Others thus: and the army, going forth to the battle line, was shouting in the battle. The ו/and does not join another statement, but is superfluous, merely joining the predicate with the subject, from which, with a few words interjected, it was separated; than which nothing is more common in the Hebrew tongue, as in 1 Samuel 25:27, and now this blessing…let it be given (וְנִתְּנָה) unto the young men (Dieu). [Concerning which see what things are on that place.] They were shouting, a great battle-cry was clearly heard in the battle line itself (Vatablus).
Shouted for the battle; as the manner was, both to animate themselves, and to terrify their enemies.
Verse 21: For Israel and the Philistines had put the battle in array, army against army.
[For Israel had put itself in array, etc., וַתַּעֲרֹ֤ךְ יִשְׂרָאֵל֙ וּפְלִשְׁתִּ֔ים וגו״] And Israel had ordered, and the Philistines, order to the meeting of order (Montanus); they had ordered battle line against battle line (Pagnine, similarly the Septuagint, Manuscripts, Syriac, Arabic, Tigurinus). The battle line of the Israelites and of the Philistines had drawn itself up, the one against the other (Junius and Tremellius).
Verse 22: And David left his carriage (Heb. the vessels from upon him) in the hand of the keeper of the carriage, and ran into the army, and came and saluted his brethren (Heb. asked his brethren of peace, as Judg. 18:15).
[Leaving the vessels, etc.] Verbatim: and he left…the vessels…upon the hand of the keeper of the vessels. The vessels of David he calls the bundle that he was bearing upon his shoulder (or rather was placed upon a beast of burden) (Sanchez out of Tostatus). The second instance of vessels he uses to refer to the heavy baggage of war (Vatablus). In this place, as often elsewhere, the Hebrew עָל יַד, upon the hand, is to be rendered between the hands (Bochart’s A Sacred Catalogue of Animals 1:2:14:196).
His carriage; the provisions which he had brought to his brethren.
Verse 23: And as he talked with them, behold, there came up the champion, the Philistine of Gath, Goliath by name, out of the armies of the Philistines, and spake (1 Sam. 17:8) according to the same words: and David heard them.
[From the camp of the Philistines, מִמַּעֲר֣וֹת פְּלִשְׁתִּ֔ים] From the grass of the Philistines (Montanus). Kimchi thinks that מַעֲרוֹת in this place signifies the plain; because their battle line was arranged in the place, or the valley under the hill, and alleges the passages out of Judges 20:33, where מַעֲרָה is rendered plain by Jonathan; that is to say, a bare and open field; for עָרָה signifies to lay bare: But, either מַעֲרָה/Maarah there signifies the proper name of a place; or it signifies cave there; or with the Septuagint it is to be read מַעֲרָב/west. Therefore, others more rightly think that a כ is wanting, and that it is to be read מִמַּעַרְכוֹת, from the ordered battle lines of the Philistines. For מְעָרוֹת are pits, caves; which signification does not fit here (Cappel’s Sacred Criticism 3:104). The Hebrew reading is twofold here: 1. in the text, מִמַּעֲרוֹת, which they render from the grass, or from the valleys; that is, from the grassy valley, where their camp was positioned; or from the disclosures, nakednesses, etc., that is, the camp lying open. See on Judges 20:33. 2. In the margin, מִמַּעַרְכוֹת (Malvenda). [Nearly all interpreters follow the Masoretic reading.] They translate it, from, or out of, the battle line (ranks [Jonathan, Tigurinus], troops, or army) of the Philistines (Munster, Pagnine, Junius and Tremellius, Arabic).
[When they had seen the man, they fled, etc. (similarly nearly all interpreters), בִּרְאוֹתָ֖ם אֶת־הָאִ֑ישׁ וַיָּנֻ֙סוּ֙] Verbatim: in seeing them the man, and they fled (Montanus); the sight of this man they were fleeing (Strigelius).
 Hebrew: וַיַּשְׁכֵּ֙ם דָּוִ֜ד בַּבֹּ֗קֶר וַיִּטֹּ֤שׁ אֶת־הַצֹּאן֙ עַל־שֹׁמֵ֔ר וַיִּשָּׂ֣א וַיֵּ֔לֶךְ כַּאֲשֶׁ֥ר צִוָּ֖הוּ יִשָׁ֑י וַיָּבֹא֙ הַמַּעְגָּ֔לָה וְהַחַ֗יִל הַיֹּצֵא֙ אֶל־הַמַּ֣עֲרָכָ֔ה וְהֵרֵ֖עוּ בַּמִּלְחָמָֽה׃  Hebrew: הַמַּעְגָּלָה.  1 Samuel 26:5: “And David arose, and came to the place where Saul had pitched: and David beheld the place where Saul lay, and Abner the son of Ner, the captain of his host: and Saul lay in the trench (שֹׁכֵ֣ב בַּמַּעְגָּ֔ל), and the people pitched round about him.”  Hebrew: הַמַּעֲרָכָה. עָגֹל signifies round.  Hebrew: וַתַּעֲרֹ֤ךְ יִשְׂרָאֵל֙ וּפְלִשְׁתִּ֔ים מַעֲרָכָ֖ה לִקְרַ֥את מַעֲרָכָֽה׃  Hebrew: וַיִּטֹּשׁ֩ דָּוִ֙ד אֶת־הַכֵּלִ֜ים מֵעָלָ֗יו עַל־יַד֙ שׁוֹמֵ֣ר הַכֵּלִ֔ים וַיָּ֖רָץ הַמַּעֲרָכָ֑ה וַיָּבֹ֕א וַיִּשְׁאַ֥ל לְאֶחָ֖יו לְשָׁלֽוֹם׃  Hebrew: אֶת־הַכֵּלִ֜ים מֵעָלָ֗יו.  Hebrew: וַיִּשְׁאַ֥ל לְאֶחָ֖יו לְשָׁלֽוֹם׃.  Judges 18:15: “And they turned thitherward, and came to the house of the young man the Levite, even unto the house of Micah, and saluted him (וַיִּשְׁאֲלוּ־ל֖וֹ לְשָׁלֽוֹם׃, and asked him of peace).”  Hebrew: וְה֣וּא׀ מְדַבֵּ֣ר עִמָּ֗ם וְהִנֵּ֣ה אִ֣ישׁ הַבֵּנַ֡יִם עוֹלֶ֞ה גָּלְיָת֩ הַפְּלִשְׁתִּ֙י שְׁמ֤וֹ מִגַּת֙ מִמַּעֲר֣וֹת פְּלִשְׁתִּ֔ים וַיְדַבֵּ֖ר כַּדְּבָרִ֣ים הָאֵ֑לֶּה וַיִּשְׁמַ֖ע דָּוִֽד׃  Judges 20:33: “And all the men of Israel rose up out of their place, and put themselves in array at Baal-tamar: and the liers in wait of Israel came forth out of their places, even out of the meadows of Gibeah (מִמַּעֲרֵה־גָבַע).”  Hebrew: וְכֹל֙ אִ֣ישׁ יִשְׂרָאֵ֔ל בִּרְאוֹתָ֖ם אֶת־הָאִ֑ישׁ וַיָּנֻ֙סוּ֙ מִפָּנָ֔יו וַיִּֽירְא֖וּ מְאֹֽד׃  Hebrew: מִפָּנָיו.