Verse 10: And as Samuel was offering up the burnt offering, the Philistines drew near to battle against Israel: (see Josh. 10:10; Judg. 4:15; 5:20; 1 Sam. 2:10; 2 Sam. 22:14, 15; Ecclus. 46:17) but the LORD thundered with a great thunder on that day upon the Philistines, and discomfited them; and they were smitten before Israel.
[While Samuel was offering] With the sacrifice begun, but not completed (Mendoza). They were seeing war brought, before they were hearing a muster (Sanchez).
[The Lord thundered, etc.] The sense of the passage is: The Philistines were stricken with terror by thunder, stricken and broken by lightning: as it is found in Ecclesiasticus 46 (Mendoza). Where with the Philistines the rulers of the Tyrians are also said to have been destroyed. For the Philistines, having been grievously afflicted by the previous plague, received to themselves external aid from neighboring people, namely, the Tyrians, and those in subjection to their rule (Sanchez). Josephus adds that the earth quaked, and, gaping with great chasms, devoured a great many (Mendoza).
They were smitten before Israel: Either by the lightnings, or thunderbolts, or other things which accompanied the cracks of thunder; or by the Israelites, who perceiving them to be affrighted and flee away, pursued and smote them, as the next verse mentions.
Verse 11: And the men of Israel went out of Mizpeh, and pursued the Philistines, and smote them, until they came under Beth-car.
[And the men of Israel, going out of Mizpeh, pursued, etc.] Question: How did they do this without weapons? Responses: 1. They had arms for civil and domestic use, although not those requisite for war. 2. The inhabitants of Mizpeh had arms. 3. The Philistines (as Josephus and Sabellicus testify) were so terrified that they cast down their arms. But the Hebrews gathered the discarded weapons (Mendoza).
And smote them: Question: Whence had they weapons wherewith to smite them? Answer: Divers of them probably brought them to the assembly; others borrowed them at Mizpeh, or the neighbouring places; and the rest might be the arms of the Philistines, which they threw away to hasten their flight, as is usual in such cases.
[To a place that was beneath Beth-car (thus the Syriac, Pagnine, Tigurinus), עַד־מִתַּ֖חַת לְבֵ֥ית כָּֽר׃] All the way beneath Beth-car (Montanus, Septuagint); to a place lying beneath Beth-car (Junius and Tremellius). Beth-car was the name of that boulder, or projection, concerning which verse 12 (Malvenda and Piscator out of Junius). Beth-car was a village, so called, either from its abundance of lambs, or from the lamb sacrificed by Samuel (Lapide). כָּר/car denotes lamb; the plural כָּרִים, lambs, Amos 6:4. This word spread to the Greeks. Certainly to Varro κὰρ/car is sheep. Hesychius: Κάρα is αἴξ/ goat, etc. כָּר/car also signifies saddle; whence בְּכַר, on the saddle, which others interpret as בָּא כַּר, a lamb came. Kimchi interprets כַּר as pasture; others, a plain, or field; that is, the same thing as כִּכָּר, with the first letter doubled. Thus בַּת/daughter, we say, and בָּבַת, the pupil (Drusius).
 Hebrew: וַיְהִ֤י שְׁמוּאֵל֙ מַעֲלֶ֣ה הָעוֹלָ֔ה וּפְלִשְׁתִּ֣ים נִגְּשׁ֔וּ לַמִּלְחָמָ֖ה בְּיִשְׂרָאֵ֑ל וַיַּרְעֵ֣ם יְהוָ֣ה׀ בְּקוֹל־גָּ֠דוֹל בַּיּ֙וֹם הַה֤וּא עַל־פְּלִשְׁתִּים֙ וַיְהֻמֵּ֔ם וַיִּנָּגְפ֖וּ לִפְנֵ֥י יִשְׂרָאֵֽל׃  Ecclesiasticus 46:17, 18: “And the Lord thundered from heaven, and with a great noise made his voice to be heard. And he destroyed the rulers of the Tyrians, and all the princes of the Philistines.” Antiquities 6:2.  Hebrew: וַיֵּ֙צְא֜וּ אַנְשֵׁ֤י יִשְׂרָאֵל֙ מִן־הַמִּצְפָּ֔ה וַֽיִּרְדְּפ֖וּ אֶת־פְּלִשְׁתִּ֑ים וַיַּכּ֕וּם עַד־מִתַּ֖חַת לְבֵ֥ית כָּֽר׃  Amos 6:4: “That lie upon beds of ivory, and stretch themselves upon their couches, and eat the lambs out of the flock (כָּרִים֙ מִצֹּ֔אן), and the calves out of the midst of the stall…”  See Genesis 31:34: “Now Rachel had taken the images, and put them in the camels furniture (בְּכַ֥ר הַגָּמָ֖ל), and sat upon them. And Laban searched all the tent, but found themnot.”  Genesis 13:10: “And Lot lifted up his eyes, and beheld all the plain of Jordan (אֶת־כָּל־כִּכַּ֣ר הַיַּרְדֵּ֔ן), that it was well watered every where, before the Lord destroyed Sodom and Gomorrah, even as the garden of the Lord, like the land of Egypt, as thou comest unto Zoar.”  Lamentations 2:18: “Their heart cried unto the Lord, O wall of the daughter of Zion, let tears run down like a river day and night: give thyself no rest; let not the apple of thine eye (בַּת־עֵינֵךְ) cease.”  Zechariah 2:8: “For thus saith the Lord of hosts; After the glory hath he sent me unto the nations which spoiled you: for he that toucheth you toucheth the apple of his eye (בְּבָבַ֥ת עֵינֽוֹ׃).”